A lot of times you may see when installing packages that apt will recommend packages, a lot of times when doing things like upgrading or install a new kernel, it is very smart at recommending related packages (eg. modules, headers, extras etc..)
All you need to do is add this flag to your "apt install" command:
--install-suggests........
apt install tftpd-hpa
#change TFTP_ADDRESS to by setting address to 192.168.1.1:69 or the IP you need, otherwise it will listen on all IPs and interfaces which could be a security risk.
# edit /etc/default/tftpd-hpa
TFTP_USERNAME="tftp"
TFTP_DIRECTORY="/srv/tftp"
TFTP_ADDRESS="192.168.1.1:69"
TFTP_OPTIONS="--secure"........
sysctl vm.overcommit_memory=1
echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo 511 > /proc/sys/net/core/somaxconn
1:M 26 Nov 2023 21:34:33.840 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
1:M 26 Nov 2023 21:34:33.840 # Server initialized
1:M 26 Nov 2023 21:34:33.840 # WARNING overcommit_memory is set to 0! Background sa........
This seems to happen in many different drivers but it happened more often in newer versions such as 530 vs 525.
Then nvidia-modeset goes to 100%
There are many reports of this appearing since driver 4.70 and I can confirm I've seen this in various machines.
https://forums.de........
Nov 15 17:00:49 rttbox kernel: overlayfs: filesystem on '/var/lib/docker/overlay2/check-overlayfs-support450709549/upper' not supported as upperdir
Nov 15 17:00:49 rttbox dockerd[93755]: failed to start daemon: error initializing graphdriver: driver not supported
The above error is often/normally caused because you are trying to run docker out of an unsuitable directory/filesystem. For example if you try to place docker's data inside an existing overl........
You may have been expecting a normal sized kernel but if you don't disable these .config options you may have a kernel that is several gigabytes.
CONFIG_SLUB_DEBUG=no
CONFIG_DEBUG_INFO=no
CONFIG_DEBUG_MISC=no
Rebuild and you should find that the kernel is the normal and as expected size.........
If you have swarm services and dockerd is creating a high load even with the containers just being idle, the easiest solution is to upgrade to a newer docker version.
For example an identical config of 3 nodes, with Redis 5 with 30 replicas produces a load of about 1.45 in Debian 10 with Docker18.09.1
If I create the same setup on Debian 11, with Docker 20.10.5+dfsg1 then the CPU usage is low.
One other difference I wondered is the kernel. In my test setup........
How to check what kernel version you have/currently running?
uname -rm
5.4.0-91-generic x86_64
The above shows us that we are running 5.4.0-91-generic on the x86_64 architecture.
The safest way is to stick with the same flavor eg if you're on generic, and say on kernel 5.4.0 then it makes sense to follow what is below. However, if you are migrating or dual booting between newer hardware (eg. you got a........
We could always disable swap but this would normally be a bad idea unless you have an incredible amount of RAM and a workload that will never exceed it. However, for live/containerized and high performance environments it could be desirable.
Another middle ground may be to set swappiness to a lower number.
You may also want to clear your kernel's cache, which could be eating up RAM unnecessarily by c........
request_module: runaway loop modprobe binfmt-464c Kernel panic - not syncing: No init found Pid: 1, comm: swapper/0 Not tainted
This is usually caused by a mismatch in architecture and happens frequently in development environments.
Here is a example of what caused this issue:
Your binaries are based on one architecture
Your kernel was compiled with another architecture.
Why does this happe........
Check your initramfs if it's missing /dev/null or /dev/console, this is likely the reason.
If you want all actual devices to be created you could also enable devtmpfs in your kernel (.config) and mount like this during init:
CONFIG_DEVTMPFS=y
CONFIG_DEVTMPFS_MOUNT=y
mount -t devtmpfs none /dev
But note devtmpfs will not create /dev/null or /dev/console for........
If you get this error in your logs:
add bridge failed: Package not installed
This error normally means one of two things.
1.) Is your brctl (bridge-utils) installed?
On Mint/Debian check for "brctl". If it's not there do
sudo apt install bridge-utils uml-utilities
2.) Is your bridge.ko (bridge kernel module loaded?).
On some installs I have seen that you cannot modpro........
This seems to have changed for RHEL 8 where a normal dracut to update your initramfs creates a system that only boots for the running kernel. For example if you have Kernel 5 and then chroot into a RHEL 8 variant which uses kernel 4.18, and run dracut, it seems that by default the system will be unbootable.
It is also the case that if you move your RAID array or drives to another server that it will be unbootable, because dracut seems to only include modules needed for the curre........
This likely works for even older versions but I have only tested on 8,9,10 (11,12). It's quite impressive at how easy it is to upgrade from a very old version to the new version. I would say that Debian version upgrades are some of the quickest and smoothest of any distro.
1.) Backup your /etc/apt/sources.list
cp /etc/apt/sources.list ~
#Get your keys first, you need the latest keys for Debian 11 or it won't work:........
You can read lots of posts about this issue but there is not much information about why this is the case or how grub determines the root= device name. Some even suggest modifying grub.cfg manually which is a disaster as the next kernel update will cause grub to revert back to the device name.
For most people this won't be an issue but those using template system, automated deployments and working in embedded may run into this issue with custom embedded and created minimal kernel........
Remember that control connections are established on port 1723 and then actual data is transferred over GRE protocol 47.
If you have a NAT setup this will work without special forwarding or accepting of GRE packets (normally if you are not blocking outgoing connections and accepting established and related connections).
The below two commands will get things going so PPTP and GRE work
We first load the ip_nat_pptp module which allows PPTP to work with........
So say you happen to have 2 NICs of the exact same chipset, they will generally show up as the same name, with possibly a different revision in lspci. Normally this is not an issue if you have a server with 4 NICs, generally the eth0 to eth3 appears from left to the right (or right to left on some vendors) so it doesn't take much figuring out.
Generally if you have different chipsets for different NICs, it should be easy to know which one is eth0 or the first NIC in the OS.........
The easiest way for the current running kernel is:
update-initramfs -u -k `uname -r`
You could change -k to a specific kernel name if for some reason the current is not running (eg. if you are chrooted or in recovery mode).
If you want to update all kernels then use "-k all"
update-initramfs -k all -u
update-initramfs: Generating /boot/initrd.img-5.4.0-162-generic........
You probably didn't do an "update-grub" and grub no longer has any proper menu entries, but before you can fix it let's try to get grub booting anyway.
If you get this lovely black grub screen here's how you can get things booting.
In my case I have a gpt partition with partition 1 and 2. Partion 1 is just my EFI / ESPand partion 2 /dev/sda2 is my root which includes /boot.
You will have to adjust this if you had a separate /boot partition.........
This article about migrating to a CentOS 7 /8 RAID mdadm array has a lot of info but I wanted to focus specifically on what newer versions of CentOS 7 require to boot mdadm and what changes are necessary on CentOS 7.8+
CentOS 7 / 8 mdadm RAID booting requirements
This assumes you are chrooting into an existing install or using it to get a new deployment ready. However, these steps can........
It may appear to be an Xorg or lightdm/gdm/mdm error but in reality for many users with this issue, it's a driver conflict and issue. I had a system that had two GPUs, an Intel and Nvidia GPU.
The only thing that got it working was to remove the nouveau driver and blacklist it so it never came back, then the Intel GPU works fine without these issues.
Solution
sudo rmmod nouveau
add nouveau/other driver to blacklist
edit th........
Here is how Ifixed it on a Mint/Ubuntu install
1.) First download the latest AMDGPU-Pro driver from here:
https://www.amd.com/en/support
Navigate to your relevant video card:
2.) Download the installer
One issue is that by default they give you a version for the latest version of........
The easiest way for the 8821AU Realtek Wifi chipset / TP-Link T2U Plus:
Bus 002 Device 003: ID 2357:0120 TP-Link Archer T2U PLUS [RTL8821AU]
First install your kernel headers/source/other required tools:
sudo apt install linux-headers-`uname -r` make gcc bc
Clone this github repo with the driver:
git clone https://github.com/morrownr/8821au-20210708
Run the compile/ins........
One easy way is to use lspci -k like this:
sudo lspci -k|grep modules|sort -nr|uniq
Kernel modules: snd_hda_intel
Kernel modules: shpchp
Kernel modules: pata_acpi
Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia
Kernel modules: mei_me
Kernel modules: lpc_ich
Kernel module........
This error implies that there may be an issue with Xorg or maybe your NVIDIA GPU cannot start or initialize:
35 laptop kernel: [ 2031.857704] nvidia: loading out-of-tree module taints kernel.
35 laptop kernel: [ 2031.857724] nvidia: module license 'NVIDIA' taints kernel.
35 laptop kernel: [ 2031.857725] Disabling lock debugging due to kernel taint
35 laptop kernel: [ 2031.873280] nvidia: module verification failed: signature a........
Linux Mint offers an easy and painless upgrade path through the last 3 versions, which means no more reinstalling to stay current with the latest version.
The only catch is that you need the latest of each version, so for 18, you need 18.3 before you can go to 19, and then 19.3 (or latest), until you go to 20. However, it's really a small price to pay and on the machines we've tested, the upgrade went seamlessly each time (although sometimes video drivers/custom kernel modules l........
Bonding is an excellent way to get both increased redundancy and throughput. It is similar to the "Network Teaming" feature in Windows.
There are a few different modes but we will use mode 6, I think it's the best of both worlds, as it is not just a failover, but it provides round robin, so you will get redundancy and load balancing. So if you have a 1G single port, you will have a combined throughput of 4G at this point. Just bear in mind that the true thr........
The Best Docker Tutorial for Beginners
We quickly explain the basic Docker concepts and show you how to do the most common tasks from starting your first container, to making custom images, a Docker Swarm Cluster Tutorial, docker compose and Docker buildfiles.........
You might assume you have a bad drive or the SATA interface/cable is bad, or the power supply is bad/weak to the drive. These are all possible issues, but definitely check your SATA cable for "twisting". It is a big issue because until the error stops or times out, your system will not boot (in my case this was the case even though the drive with the issue was not part of the OS or booting process at all).
If you run an open rig that you move around often that ha........
There aren't too many simple guides that show you how to use commands to setup your USB or other drive as a normal bootable drive where you can easily boot custom kernels or whatever OS you would like.
1. Get the tools we need:
We install "syslinux" for MBR and "syslinux-efi" for EFI and "MBR" as we need a tool that embeds the actual MBR into our USB:
sudo apt install syslinux syslinux-efi mbr........
If you are using the stock 5.4 kernel this is normal but I can confirm it is fixed in newer 5.8 kernels.
To fix it just install the 5.8 kernel and reboot:
sudo apt install linux-headers-5.8.0-64-generic linux-modules-extra-5.8.0-64-generic linux-image-5.8.0-64-generic........
Enable "cli" mode equivalent in JunOS
cli
Configure Mode
configure
So rather than going to the console on a Cisco switch and typing "enable" and then "conf t", the equivalent in JunOS is "cli" and "configure".
How Do You Apply Changes You've Made?
You can make all kinds of changes to the switch, but remember they are not........
Traditionally kernels were numbered starting from 0 but by default the "new style" of grub boot loading considers each subkernel item to be different so if you have 3 entries for 4.40-148 rather than counting for 1.
To get the expected behavior let's show this example and how we can boot it
We do a grep on menuentry in /boot/grub/grub.cfg to see all of the bootable kernels rather than scrolling through loads of extra entries we don't care about (thou........
The problem seems to be that whatever kernel and initrd you have is tied to an old version of CentOS 7 that is no longer in the current repos of most mirrors.
If you were previously able to PXEboot and install CentOS and you are sure your network and tftp are good the problem is that you have an outdated kernel and initramfs that point to a defunct version.........
Interestingly enough Windows 2000 works fine on QEMU 64-bit but you have to specify Pentium as your CPU otherwise it doesn't complete the install (it will not pass the detecting/setting up devices phase).
-vga cirrus is wise because it is supported by Windows 2000 and allows higher resolutions and 24-bit color.
-cpu Pentium emulates an old computer and is necessary for install to complete
-device rtl8139 is important as this oldschool Realtek 8139 NIC is supported by W........
It took a lot of fiddling to make a Huion Kamvas 13 Pro work in Linux but it simple once you know what to do. Don't bother searching as it is unlkely there is a guide out there that will actually make your tablet work.
It mainly comes down to the fact that the hid_uclogic kernel module is buggy or doesn't support MANYof these wacom based/Huion tablets properly.
What was happening with me is that Ihad the Kamvas 13 Huion setup as a secondary screen/monitor.&nb........
This happens to a lot of Nvidia users especially users of newer cards like the RTX series. If for example you are trying to boot and install Linux and you get a black and white grub2 screen instead of a nice graphical welcome installer, you probably suffer from this bug. It is normally followed by the user booting and finding they just have a blank/black screen.
Here is the quick flow of steps to fix it:
If you get a black grub scree........
kernel: [549267.368859] mate-terminal[7871]: segfault at 2000000101 ip 00007f5d0a9548f0 sp 00007fff7012c610 error 4 in libgobject-2.0.so.0.4800.2[7f5d0a920000+52000]
This seems to be a long-time bug in Mint mate-terminal where you sometimes move or detach a terminal and it crashes losing all of the other open terminal sessions.........
If you've come here, don't be embarraassed, working in IT, this is the MOST common computer problem that almost everyone will encounter. The reason why I'm doing this post is because I've seen an increase from colleagues and admins having this problem and many times it's not even your fault. A common scenario is that someone acquires a new or used computer which they weren't given the password for. Fortunately Ihave a detailed list of all the options whether free or pa........
I was using a small box as a router and one of the ports started going off and coming back at 100M. I truly believe it is simply that it was a case of overheating. Although CPUtemps were only about 67 degrees, the physical box itself was almost burning hot. Isolved the cooling issue and never had the issue again.
Jul 28 15:09:27 swithbox kernel: e1000e: eth1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
Jul 28 15:09:28 swithbox kernel:........
You should only get this if you are using a Pentium II or something really old. The problem here is that newer kernels than 2.6 don't have true i386 support even if you tell it to compile as i386. It will still include features like cmov that break older computers from being able to work.
Generally for very old computers like above, you need to use a 2.6.x kernel and of course make sure it is i386 and all the binaries are as well.
........
This is very frustrating but the fix is usually easy once you read this blog. It's very frustrating when you find that your Linux / Ubuntu laptop's wifi will NEVER work unless it is plugged into the power. The wifi menu may say "Wifi disabled by hardware switch". You may find that your laptop has no switch or has a function wifi button on the keyboard but this does not work or have any effect.
The cause is usual a "wmi" kernel module and simply doing an........
yum -y install gcc make gperf genisoimage flex bison ncurses ncurses-devel pcre-devel augeas-devel augeas readline-devel
checking for cpio... cpio
checking for gperf... no
configure: error: gperf must be installed
configure: error: Package requirements (augeas >= 1.2.0) were not met:
Requested 'augeas >= 1.2.0' but version of augeas is 1.0.0
yum remove augeas augeas-libs augeas-devel
wget http://downl........
chroot /root/kvmguests/4591915/mount
FATAL: kernel too old
This happens for example if you are in Centos 6 and trying to chroot into a system based on a newer kernel like 4.x+
You'll have to use a newer OS/kernel system to chroot into the environment or a VM running a newer kernel.........
apt install software-properties-common
add-apt-repository ppa:deadsnakes/ppa
apt update
apt install python3-pip
apt install python3.7 curl gnupg python3.7-dev git
ln -s /usr/bin/python3.7 /usr/bin/python3
pip3 install numpy keras_preprocessing
curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add -
echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel........
Most newer distros inexplicably cause your NIC to have what Icall "random" non-standard name conventions because of systemd.
This is a big problem for many people and especially those running servers. Imagine that you have a static IPconfigured for ens33 but then the hard disk is moved to a newer system, the NIC could be anything from ens33 to enp0s1, meaning that manual intervention is required to go and update the NIC config file (eg. /etc/network/interfa........
I used to believe that for Desktops especially that the "ondemand" CPUfrequency changing that kernels included with Ubuntu and Debian based distros have would be sufficient for snappy performance.
However, you can feel the lack of performance on the fastest computer if you have ondemand. A lot of times even under high load 100% of your CPUfrequency in MHz will not be used.
For example a 2.8Ghz CPUmay only run at 1.8MHz or even .9GHz. Now........
Occasionally my whole screen locks up and I cannot even swith to the console and I find this in my syslog:
*-display
description: VGA compatible controller
product: Mullins [Radeon R3 Graphics]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
 ........
This is only really necessary in the case you don't want DHCP. If you are dealing with an encrypted LUKS server on the internet, you will often want to have a static IP so you know which IP to connect to (or if you have a semi-static IP assigned by DHCP).
SET IP Address by /etc/initramfs-tools/initramfs.conf
IP Address=192.168.1.27
Gateway=192.168.1.1
Subnet Mask: 255.255.255.0
Hostname=myhome.com
IP=192.1........
The cool thing here is that we only need 1 drive to make a RAID 10 or RAID 1 array, we just tell the Linux mdadm utility that the other drive is "missing" and we can then add our original drive to the array after booting into our new RAID array.
Step#1 Install tools we need
yum -y install mdadm rsync
Step #2 Create your partitions on the drive that will be our RAID array
Here I assume it is /dev........
This is the reason that I don't like the new ADATA USB drives such as the UV128/64GB or 128GB drives and other ones that look to be the same style (the green sliding USB connector).
They just don't work well from new and never work properly at any point.
[ 788.242463] usb 1-1.2: new high-speed USB device number 16 using ehci-pci
[ 788.339816] usb 1-1.2: New USB device found, idVendor=125f, idProduct=db8a
[ 7........
This problem has been around forever, Linux seems to think it is fine to use the r8169 driver for an r8168 NIC but this often causes problems including the link not working at all.
In my case ethttool shows the link up and detected but it simply does not work especially on a laptop that has been resumed from suspension. Sometimes it takes several minutes for it to work or to unplug and replug the ethernet.
Here is the solution:
Install th........
Use fdisk on your USB drive to create a bootable NTFS partition (in my case /dev/sdb):
sudo fdisk /dev/sdb
Welcome to fdisk (util-linux 2.27.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)........
This is all controlled by /etc/issue
You can basically enter anything in there that you like, but there are preset variables that are mentioned at the end of the page that discuss this.
Some examples of /etc/issue:
Centos 7:
S
Kernel r on an m
Ubuntu 16.04:
Ubuntu 16.04.6 LTS n l
You can also insert any of t........
I think this is more so an issue with kernel modules not being included. I had this issue on Linux Mint because a new kernel I upgraded to DIDNOT have the "extra" modules and part of that reason is also because older kernels are named differently than new ones.
Take this example article below that shows it in action.
If you were previously........
I don't consider a lot of these "extra" kernel modules "nice to have" as they often contain drivers for essential items like your soundcard, your NIC and many other devices that may not work. Sometimes you may find that "sound" or "ethernet" worked before a kernel/OS upgrade and now in the new version they don't. Often it will be because you need to install the "extra" kernel modules.
One other weird thing is that sometimes........
If you've just installed VBox and it is not starting or working, the most common problem is usually that you don't have your kernel source installed, which means there is no kernel driver for vbox so it can't work.
You may get an error that says "Kernel driver not installed" in your Virtualbox.
So the first thing you should do is install your kernel source by running this:
sudo apt-get install linux-headers-`uname -r`........
This is the closest way to disabling it without using the "libata.force=noncq" kernel boot option is to set the queue to a depth of 1 which doesn't actually disable it.
Change the sdc below to match the device you want to disable NCQ for.
[root@officebox ~]# echo "1" > /sys/block/sdc/device/queue_depth
Errors that indicate you are having a performance issue are these in messages or dmesg relating to N........
gsmartcontrol is a free tool that let's you see the status of the SMART parameters so you can check things like temperature, reallocated sectors, bad sectors etc.. to give you a better idea of your drive health.
Download it here.
gsmartcontrol is a very useful tool in Windows to check your HDD / Hard Drive health status.
In my experience you should NEVER trust that everything is OK just because SMAR........
If you don't aleady have it, you'll need EPEL
Install LXC
yum -y install lxc lxc-templates
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.it.ubc.ca
* epel: mirrors.kernel.org
* extras: mirror.it.ubc.ca
* updates:........
Idid a systemctl restart networking and it broke Proxmox VM connectivity!
#proxmox is the problem after restarting the network the tap devices go to disabled state
[2230884.919905] vmbr0: port 7(tap118i0) entered disabled state
[2230884.948864] vmbr0: port 8(tap122i0) entered disabled state
[2230884.972748] vmbr0: port 6(tap119i0) entered disabled state
[2230885.004745] vmbr0: port 5(tap117i0) entered disabled state
[2230885.03673........
I tried to stop a qemu-img copy or clone and it broke everything. It was fine to "stop" it from the GUI but a process still persisted so I killed the relevant qemu-img and the kernel went crazy. It also may not have helped that I tried to lvremove a different volume (an unused disk). But either way it breaks LVM (you cannot even run lvdisplay) so a reboot is necessary.
Jan 17 06:45:21 testserver kernel: [ 5680.439337] systemd-udevd D 0&nbs........
On a test machine Iwas never able to access to a newly created 4th partiton. As we can see there are dev devices for everything but the 4th partition.
The normal "partprobe" or "kpartx" or kernel being told to rescan the block device didn't help (only a reboot did).
fdisk -l /dev/sda
Disk /dev/sda: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units........
In a RAID array I had a have periodically lost a drive here and there over the past several months. Iwas always able to readd and resync without losing data. However at some point it looks like some minor corruption happened and this makes DRBD unhappy.
Using fsck did not help either.
Dec 19 06:01:45 storageboxtest4 kernel: [19005.945890] EXT3-fs error (device drbd0): ext3_get_inode_loc: unable to read inode block - inode=22184379........
mdadm --manage /dev/md125 -a /dev/sdb4
mdadm: add new device failed for /dev/sdb4 as 3: Invalid argument
Dec 19 01:23:48 storageboxtest kernel: [ 2328.854491] md: sdb4 does not have a valid v1.2 superblock, not importing!
Dec 19 01:23:48 storageboxtest kernel: [ 2328.854499] md: md_import_device returned -22
#zero the superblock and try again!
mdadm --zero-superblock /dev/sdb4
mdadm --ma........
Before getting into the output here is my typical experience with SMART, there is what I call a "bad disk" with pending and uncorrectable sectors that cannot be reallocated.
It has caused a kernel panic and system crash repeatedly as we can see from the logs.
But SMART says it has "PASSED" its self assessment. SMART is still useful to me but it is more about looking at Current_Pending_Sector.
Any time I have had anything but 0 for that attribute it........
systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system.
The key commands or arguments you will use with systemctl are the following:
Unit Commands:
list-units [PATTERN...] List loaded units
&nbs........
4.374647] usb_common: exports duplicate symbol usb_get_dr_mode (owned by kernel)
[ 4.403334] usbcore: exports duplicate symbol __usb_get_extra_descriptor (owned by kernel)
[ 4.427736] xhci_hcd 0000:00:15.0: xHCI Host Controller
[ 4.427844] xhci_hcd 0000:00:15.0: new USB bus registered, assigned bus number 1
[ 4.429040] xhci_hcd 0000:00:15.0: hcc params 0x200077c1 hci version 0x100 quirks 0x01109810
[ 4.429141] xhci_hcd 0000:00:15.0: cache line size of 64 is not sup........
[root@localhost:~] vmkping -I vmk1 10.0.2.69
PING 10.0.2.69 (10.0.2.69): 56 data bytes
sendto() failed (Host is down)
vsphere distributed switch vmotion not working
[root@localhost:~] esxcfg-route -l
VMkernel Routes:
Network Netmask Gateway Interface&........
You can search for this bug and it seems like it may be related to ecryptfs and is many years old.
The symptoms are that you return to the computer and the screensaver was active or the screen was asleep/black and it doesn't seem to come back. But you check by SSH the computer is running fine and are frustrated you'll lose your running programs and have to reboot.
There is a simple solution:
Ctrl + Alt + F1
Ctrl +Alt + F8
Ba........
sudo apt-get install nfs-kernel-server #oops there are no exports so it won't startsudo /etc/init.d/nfs-kernel-server start* Not starting NFS kernel daemon: no exports.
#we will use the /tmp/nfstestshare directory for our NFS share
mkdir /tmp/nfstestshare
#add it to /etc/exports (basically what NFS checks to determine what to make an NFS share)
/tmp/nfstestshare 192.168.1.5(rw,sync,........
I had this error in an unsupported CPUon VMWare 6.7 and apparently this sometimes works especially on older VMWare versions like 6.5 5.5 etc (but in my case it did not).
To make sure it proceed when you see "Loading VMWare"
Hit "Shift+O"
Then add "ignoreHeadless=TRUE"
See an example below:........
This is not the normal "black screen"issue and I was shocked to eventually find out why. The normal advice of reconfiguring Xorg didn't work. Even booting into "Recovery Mode" did not help.
Here is the short end of the stick that fixed it:
sudo apt-get install mdm mate-desktop-environment
Yes you got it right, mdm and the mate-desktop-environment / gnome were somehow uninstalled. This must be whe........
ValueError: new value non-existent xfs filesystem is not valid as a default fs type
Pane is dead
From what Iread this is misleading and has to do with the fact that the initrd and kernel are mismatched.
This is a hard situation because for some older hardware Iam using the Centos Plus kernel which has modules that Irequire for an older server/NIC. This seems to have cropped up in the past few months and there is no simple fix........
It looks like this has something to do with APIC but I am not sure. I have similar CPUs with a different MB and BIOS that work fine on the same type of kernel. A lot of time the issue is because of the C-step setting in the BIOS.
The same thing happened on the 2.6 kernel with Centos 6 but this is a homebrew 4.4 kernel soI am not sure why it is happening when even Centos 7 (3.2) kernel works OK.
Solution - It comes down to the BIOS set........
It is well known hackers, the NSA, CIA and other groups have created malware to secretly turn on your webcam and microphone on your phone, tv etc.. But fortunately on our computers and laptops we have some options.
Most webcams use the "uvcvideo" kernel module / driver. You can disable this in two ways on boot. I recommend both just as a failsafe.
Disable it on rc.local once your system boots automatically
Add the followi........
Error: Unable to apply new quota values: quota not running
Container start failed (try to check kernel messages, e.g. "dmesg | tail")
Killing container ...
Container was stopped
Error: Unable to apply new quota values: quota not running
Can't umount /vz/private/123123: Invalid argument
[root@rtt 123123]# vzquota on 123123
vzquota : (error) Can't open quota file for id 123123, maybe you need to reinit........
I've never seen this before in all of my years. Ihave some very old CDs and DVDs 12-15 years old that seem not to work in this BD-R/DVD-R/CD-R Asus drive.
The discs are fine actually and ironically they even work fine on a normal LG USB based BD-R drive!
Here are the errors in Linux:
[2914936.884924] attempt to access beyond end of device
[2914936.884927] loop1: rw=0, want=730424, limit=688384
[2914954.556873] attempt to........
This guide will work for most modern Linux versions like Centos RHEL 7, Debian, Mint, Ubuntu etc...
In Centos 7 the days of editing the "kernel"line and adding "single"are gone. On top of that sometimes after a new install passwords do not work, maybe you forgot your password or for some other reason you need to break in or fix your system? It could also be because you can't mount your root / or some other /etc/fstab error and many other err........
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/geoip.so' - /usr/lib64/php/modules/geoip.so: undefined symbol: GeoIP_country_code_by_name_v6 in Unknown on line 0
Remove the GEOIP from PHP:
php71w-pecl-geoip-1.1.1-1.w6.x86_64
PHP Fatal error: PHP Startup: apc_shm_create: shmget(0, 67108864, 914) failed: Invalid argument. It is possible that the........
Install requirements:
yum -y install gmp-devel mpfr-devel libmpc-devel glibc-devel glibc-devel.i686 zip unzip jar
Download, untar, configure, compile and install GCC
http://mirrors.kernel.org/gnu/gcc/gcc-5.5.0/gcc-5.5.0.tar.gz
tar -zxvf gcc-5.5.0.tar.gz
cd gcc-5.5.0
./configure
make
make install
Now you need to cleanup th........
The Linux Kernel interpretated a very high volume of real traffic as a DDOS attack so it basically ends up blocking your web server.
possible SYN flooding on ctid 42131, port 80. Sending cookies.
Simple fix edit sysctl values for max_syn_backlog
sysctl -w net.ipv4.tcp_max_syn_backlog=5000
To make them permanent edit /etc/sysctl.conf
echo "net.ipv4.tcp_........
yum -y install samba
vi /etc/samba/smb.conf
https://www.kernel.org/pub/linux/utils/boot/syslinux/syslinux-6.03.zip
mkdir syslinux;cd syslinux;unzip syslinux-6.03.zip
mkdir -p /tftpboot/libs/
cp bios/com32/modules/linux.c32 /tftpboot/libs/
cp bios/com32/libutil/libutil.c32 /tftpboot/libs/
cp bios/com32/lib/libcom32.c32 /tftpboot/libs/
#add lib path
echo "PATH libs" >> /tftpboot/pxeli........
Normally lspci will show you just like this and would suggest they are exactly the same card:
1a:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/580] (rev e7)
1c:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/580] (rev e7)
lspci -vnn is the answer
As we can see one is a Gigabyte and the other is an MSI card. Wha........
iptables -t NAT -A PREROUTING -s 24.30.44.0/24 -j DNAT --to-destination 10.10.10.1
iptables v1.4.7: can't initialize iptables table `NAT': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
Solution
# it is case sensitive "nat" and DO NOT use "NAT" or you will get this error!
iptables -t nat -A PREROUTING -s 24.30.44.0/24 -j DNAT --to-destination 10.10.10.1........
I have never had this error on Linux and this is running FreeBSD as root:
Wed Aug 9 04:29:34 2017 us=329050 Cannot allocate TUN/TAP dev dynamically
Wed Aug 9 04:29:34 2017 us=329832 Exiting due to fatal error
The Solution you need a kernel module that is for some reason not automatically loaded like Linux:
kldload if_tap........
Iam not sure why this is happening neither the hostnode or VM changed. All I did was reboot the hostnode and startup the Centos VM again, also note it happened with the original kernel on the VM and also the latest 6.9 kernel as of this writing as shown below.
Host Node: Centos 6.9
Kernel:2.6.32-696.6.3.el6.x86_64
Kernel: 2.6.32-042stab123.9
Same result in any kernel above........
I have never had this error on Linux and this is running FreeBSD as root:
Wed Aug 9 04:29:34 2017 us=329050 Cannot allocate TUN/TAP dev dynamically
Wed Aug 9 04:29:34 2017 us=329832 Exiting due to fatal error
The Solution
You need a kernel module that is for some reason not automatically loaded like Linux:
kldload if_tap........
[1035724.274610] [drm:intel_pipe_update_end [i915_bpo]] *ERROR* Atomic update failure on pipe A (start=62076478 end=62076479) time 102 us, min 894, max 899, scanline start 893, end 900
W: Possible missing firmware /lib/firmware/i915/kbl_dmc_ver1.bin for module i915_bpo
I've been getting those errors on a J3455 NUC box with the latest kernel on Linux Mint 18.2. When updating the initramfs I also got the error about the firmware........
Essentially a program I was running for mining did not terminate properly with Ctrl+C it is listed as defunct and cannot be killed, kernel is tainted and normal tricks to disable the port are impossible the dev and sys entries for the device cannot be browsed or interacted with in any form without a lockup of the request. The only solution is to reboot due to the kernel taint as far as I can find so far.
[1130246.811056] INFO: task minerd:21861 blocked for more th........
This container won't start after exhausting its memory. There are no relevant or helpful messages in dmesg or vzctl.log as well. Standard troubleshooting such as disabling PPP etc has not helped.
2017-07-06T23:33:29-0400 vzctl : CT 888171 : Locked by: pid 166029, cmdline vzctl start 888171
2017-07-06T23:33:29-0400 vzctl : CT 888171 : Container already locked
2017-07-06T23:33:29-0400 vzctl : CT 888171 : Container was stopped
2017-07........
Done on Centos 7.3 very important as clearly based on older guides it was a lot easier and more simpler! Hint do not use grub2-install!
If you have trouble booting after this check this CentOS mdadm RAID booting/fixing guide.
One huge caveat if you are an oldschool user or sysadmin who has avoided UEFIbooting
The nor........
This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver. The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether.
Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
I am using a GTX 1060 but replace the download for the driver with the correct/current version for your particular card by visiting: http://www.nvidia.com/Download/index.aspx?lang=en-us
yum install automake curl openssl-devel libcurl-devel gcc gcc-c++
yum -y install kernel-devel-`uname -r`
yum -y install unzip
#the........
Why won't my Linux Mint boot after I manually installed a new kernel?
eg.
apt-get install linux-image-newerone
Do this
dpkg -l|grep linux-image|grep extra
ii linux-image-extra-3.16.0-38-generic 3.16.0-38.52~14.04.1&nb........
When running cudaminer once it tries to initialize the card the entire screen freezes. The computer itself is still running but the Xorg is done for, you cannot even switch to another console window and must reboot (even an mdm or Xorg restart does not help).
At first cudaminer will give you these errors:
stratrum_recv_line failed
...retry after 15 seconds
GPU #0: Geforce 210 with compute ca........
*Update so this doesn't work it must be something to do with the path of nfs or something else but the installer fails with "Installer crashed" at the end whereas with the CD/USB it works.
This assumes you've already installed and configured a separate PXE/DHCP server somewhere else and your /tftpboot directory is setup.
This is for Linux Mint 18.1 but generally applies to most versions although you may have tro change things like "casper"........
Normally the below would indicate a failing or failed drive. In this case the SATA port was unplugged and sometimes the Linux kernel/motherboard even with AHCIjust don't play nice and can't handle it.
What happened is Iplugged in a new drive after removing another one. However the log shows that after the old drive was plugged in the Linux kernel kept complaining thinking the drive was there but not responding properly. This continued even with reseating........
In short the two drives in the array were /dev/sdd and /dev/sde. The kernel sees they were unplugged and have gone down as you can see below.
mdadm caught the first one being unplugged /dev/sde and disabled the missing drive. However when the final drive that was part of the array is unplugged it didn't notice at all. Instead it complains about an IO error later for drives that the kernel knows do not exist anymore.
[45817.162728] ata4: exception........
mdadm won't boot in Ubuntu/Mint/Debian anymore.
You just get the following in a loop:
mdadm: CREATE group disk not found
Incrementally started RAID arrays.
Incrementally starting RAID arrays...
mdadm: CREATE group disk not found
Incrementally started RAID arrays.
Incrementally starting RAID arrays...
mdadm: CREATE group disk not found
Incrementally started RAID arrays.
Incrementally starting RAID arrays...
mdadm: CREATE group dis........
This was a surprising bug but I unplugged all drives for an array md127. At first it was just 1 drive and mdadm seemed to notice this. I unplugged the second drive taking the array offline but mdadm did not realize it was offline and still showed a non-existent disk as being part of it. This created problems trying to unmount it or even to stop this array with mdadm freezing.
As for how to fix it I can only think of making sure you are not in a mounted path of........
Uh oh
[17925926.174277] block drbd0: Handshake successful: Agreed network protocol version 96
[17925926.174325] block drbd0: conn( WFConnection -> WFReportParams )
[17925926.174342] block drbd0: Starting asender thread (from drbd0_receiver [1682])
[17925926.174432] block drbd0: data-integrity-alg:
[17925926.174581] block drbd0: drbd_sync_handshake:
[17925926.174586] block drbd0: self 2AAE66AF9252D6DB:2815BF........
PHP Fatal error: PHP Startup: apc_shm_create: shmget(0, 67108864, 914) failed: Invalid argument. It is possible that the chosen SHM segment size is higher than the operation system allows. Linux has usually a default limit of 32MB per segment. in Unknown on line 0
PHP Fatal error: PHP Startup: apc_shm_attach: shmat failed: in Unknown on line 0
This error is not at all fun because it actually prevents Apache/httpd from starting or working at all. It will........
2017-01-12 14:25:36 529 (ERROR): The installer was unable to verify that your kernel supports IPv6.
2017-01-12 14:25:36 530 (ERROR): The message received when trying to create an IPv6 socket was Address already in use
2017-01-12 14:25:36 531 (ERROR): Please ensure that the ipv6 module is enabled and loaded in your kernel.
2017-01-12 14:25:36 532 (FATAL): Exiting...
Solution
This happened........
# yum -y install qemu-kvm
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.lzu.edu.cn
* elrepo: ftp.utexas.edu
* epel: ftp.jaist.ac.jp
* extras: mirrors.aliyun.com
* openvz-kernel-rhel6: mirror.fdcservers.net
* openvz-utils: mirror.fdcservers.net
* updates: mirrors.nwsuaf.edu.cn
Resolving Dependencies........
I created a new partition table on a newly plugged in device and it caused fdisk to hang (even force kill does not work). It also may be a bad drive or some other issue because fdisk -l hangs after the first 2 HDDs (totaly of 8 HDDs on this system):
[1232879.903596] INFO: task fdisk:27176 blocked for more than 120 seconds.
[1232879.903607] Tainted: P&nbs........
It is already known this is not possible
mdadm --create /dev/md3 --level 10 --layout=f2 --raid-devices=2 /dev/sdc1 /dev/sdd1
mdadm: /dev/sdc1 appears to be part of a raid array:
level=raid10 devices=2 ctime=Sat Dec 24 18:44:29 2016
mdadm: /dev/sdd1 appears to be part of a raid array:
level=raid10 devices=2 ctime=Sat Dec 24 18:44:29 2016
Continue creating ar........
sudo fdisk /dev/sdh
WARNING: GPT (GUID Partition Table) detected on '/dev/sdh'! The util fdisk doesn't support GPT. Use GNU Parted.
WARNING: The size of this disk is 8.0 TB (8001563221504 bytes).
DOS partition table format can not be used on drives for volumes
larger than (2199023255040 bytes) for 512-byte sectors. Use parted(1) and GUID
partition table format (GPT).
The device presents a l........
forcedeth 0000:00:08.0: irq 25 for MSI/MSI-X
forcedeth 0000:00:08.0: eth0: MSI enabled
forcedeth 0000:00:08.0: eth0: no link during initialization
ADDRCONF(NETDEV_UP): eth0: link is not ready
forcedeth 0000:00:08.0: eth0: link up
ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Dec 1 18:21:32 box15 kernel: forcedeth: Reverse Engineered nForce ethernet driver. Version 0.64.
Dec 1 18:21:32 box15 kernel........
The only solution after trying many suggestions was to simply restart the "vz" service (definitely not preferable).
Even doing an ifdown and ifup for venet0 did not help.
ifup venet0
Bringing up interface venet0:
Configuring interface venet0:
net.ipv4.conf.venet0.send_redirects = 0
RTNETLINK answers: Network is down
Some errors from log:
CPT ERR: d2dc60........
md127 issue, it should be /dev/md3 per mdadm.conf
Any time something is mounted as md127 it almost always means there is no entry for this mdadm array in the mdadm.conf in initramfs (which is separate from your actual /etc/mdadm.conf).
cat /etc/mdadm.conf
ARRAY /dev/md3 metadata=1.2 UUID=b6722845:381cc94e:7a2c5b5f:8e3b7c4f
The reason for this is something strange, most Linux OS's bizarrely always keep their own copy of /etc/mdadm.con........
Now many people report this card simply not working in various Linux distros and kernels. My issue is different, it always works at 100mbit (eg. plugged into a 100mbit switch) but no matter what 1000M/gigabit switch I would try, it would never work.
The link would be up (the lights were on) and the OS detected the link as being up as well but it wouldn't work at all and could not pass data in or out (not even a ack/ping).
There is one simple solution and command........
Tired of checking iotop and seeing that your drbd partition is using 99.99% of io all the time and finding your drbd device performs slow in general?
This is especially an issue in versions of DRBD in the 8.3 tree in particular one documented case is on "8.3.13" but it likely applies to other devices.
The symptoms are that resyncing is fine and normal but any reasonable amount of activity is very slow and lagged and creates a high server load and con........
To disable NCQ in the Linux kernel (change sda to match your device).
echo 1 > /sys/block/sda/device/queue_depth
To enable NCQ (change sda to match your device).
echo 31 > /sys/block/sda/device/queue_depth........
vzkernel-2.6.32-042stab116.2.x86_64.rpm&n........
We've all done this at some point, you work on the wrong shell window and this was my first time making this mistake but I deleted a partition table in fdisk, recreated it and saved it with "wq" and even ran partprobe! If you haven't rebooted yet then you can still recover your partition table, otherwise you're in big trouble.
Fortunately since it was a live system and in use the kernel still had to use the old table like below:........
This happened while an mdadm array was syncing, all access from writing a new blank file to opening a small .txt file was very slow:
[222117.312078] kjournald starting. Commit interval 5 seconds
[222117.685060] EXT3-fs (md0): using internal journal
[222117.685096] EXT3-fs (md0): mounted filesystem with ordered data mode
[222122.376847] kjournald starting. Commit interval 5 seconds
[222122.602825] EXT3-fs (md2): using internal jour........
Errors like this are shown on high usage servers and ports so it is common to see it on http and even imap ports:
possible SYN flooding on port 80. Sending cookies.
The Linux kernel will even detect flooding on OpenVZ containers:
possible SYN flooding on ctid 6000, port 993. Sending cookies.
In many cases this is not an issue and is more so simply a result of regular, but high usage traffic.........
kernel: [10186978.064405] TCP: time wait bucket table overflow (CT3)
Varying opinions are out there but in general it seems like the most common culprit is a lack of privvmpages, with a modern OpenVZ system the best way is to set privvmpages as equal to what your RAM is and this has resolved the messages on another system.
If it's truly a TCP issue you can adjust the following parameters:........
It all comes down to a bug essentially where you are running an older kernel that doesn't support the newer Debian templates. The solution is to update your OpenVZ kernel.
Here are some symptoms of the problem/lack of kernel support:
Ubuntu Template 12.04 requires a manual network start:
service networking start
sshd will not start:
/usr/sbin/sshd
PRNG is not seeded
mknod /dev/random c 1 8........
grub> root (hd0,0)
root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub> setup (hd0)
setup (hd0)
But if you do:
root (hd1,0)
setup (hd1)
it does work, I think hd0/sda had a GPT partition that was not removed properly (what I did was just dd bs=512 count=1 the partition table from another drive since the partition table should be identical).
Checking if "/boot/grub/........
In plain English this happens after you upgrade VBOX and it rebuilds kernel modules based on a newer kernel than you are running (eg. you upgraded your kernel but haven't booted into it).
It is too bad there is not a standard work around that would allow it to realize this and keep old kernel modules and use them if it detects your current kernel is older than the most recently build modules.
===============
RTR3InitEx failed with rc=-1912 (rc=-1912)
The........
I am getting this error:
kernel:[14277.697049] EDAC MC0: UE row 4, channel-a= 0 channel-b= 1 labels "-": (Branch=0 DRAM-Bank=0 RDWR=Read RAS=7048 CAS=0 FATAL Err=0x4 (>Tmid Thermal event with intelligent throttling disabled))
But many people believe this is a bug/false message and the server is running stably.........
It sounds like this is corrected in later versions of the OpenVZ kernel but Iam not sure, it may also be that a much newer kernel is needed and Centos may not have a recent enough kernel.
*Debain 7.0 however does work fine as a temporary fix or work around.
Debian 8 OpenVZ no IP and networking not working:
lo Link encap:Local Loopback
 ........
Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason. Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to? In some cases on a remote system you can't easily reinstall without physical or KVM access.
So in this case you add a second physical or disk or already ha........
#solution
Edit /etc/yum.repos.d/openvz.repo
For the first two entries comment out #mirrorlist and uncomment #baseurl and then it worked
openvz yum problem Centos 6.5 cannot find file on mirror:
yum update
Loaded plugins: fastestmirror
Determining fastest mirrors
* openvz-kernel-rhel6: mirrors.ustc.edu.cn
* openvz-utils: mirrors.ustc.edu.cn
base ........
The solution was to reinstall the vbox dkms package and do a manual modprobe of the modules it makes.
I never sorted out the unable to start due to the USB issue, I did have the guest additions installed but the only way to boot was to change the pointing device from USB to PS2 and then to disable the USB controller (if your pointing device is set as USB, disabling USB will not work because it will re-enable by default when it sees your pointing device is USB, this is w........
[ 2868.041375] ata1: EH in SWNCQ mode,QC:qc_active 0x40 sactive 0x40
[ 2868.041554] ata1: SWNCQ:qc_active 0x40 defer_bits 0x0 last_issue_tag 0x6
[ 2868.041556] dhfis 0x40 dmafis 0x40 sdbfis 0x20
[ 2868.041874] ata1: ATA_REG 0x41 ERR_REG 0x84
[ 2868.042013] ata1: tag : dhfis dmafis sdbfis sactive
[ 2868.042163] ata1: tag 0x6: 1 1 0 1
[ 2868.042301] ata1.00: exception Emask 0x1 SAct 0x40 SErr 0x400000 action 0x6 frozen
[........
yum -y install wget
wget -P /etc/yum.repos.d/ http://ftp.openvz.org/openvz.repo
rpm --import http://ftp.openvz.org/RPM-GPG-Key-OpenVZ
yum -y install vzkernel vzctl
#enable ip_forward
sed -i s/'net.ipv4.ip_forward = 0'/'net.ipv4.ip_forward = 1'/g /etc/sysctl.conf
#all interfaces should not send redirects
echo "net.ipv4.conf.default.send_redirects = 1" >> /etc/sysctl.conf
echo "net.ipv4.co........
Message from syslogd@server at Sep 14 11:35:59 ...
kernel:[Hardware Error]: MC4 Error (node 1): DRAM ECC error detected on the NB.
Message from syslogd@server at Sep 14 11:35:59 ...
kernel:[Hardware Error]: Error Status: Corrected error, no action required.
Message from syslogd@server at Sep 14 11:35:59 ...
kernel:[Hardware Error]: CPU:6 (10:8:0) MC4_STATUS[Over|CE|MiscV|-|AddrV|CECC]: 0xdc00400021080813........
I'm not sure why I'm getting these but all memory modules are the exact same and all passed memtest successfully although they are ECC. I've heard that ECC RAM can't be tested as well and the kernel seems to indicate they are non-fatl recoverable errors. I wonder if the BIOS has aggressive RAM timing or maybe the controller or motherboard is bad.
[ 12.716515] EDAC MC: Ver: 2.1.0
[ 12.717771] EDAC MC0: Giving out device to........
[ 17.208336] tg3 0000:08:00.0: eth0: Link is up at 1000 Mbps, full duplex
[ 17.210194] tg3 0000:08:00.0: eth0: Flow control is on for TX and on for RX
[ 76.000065] phy0 -> rt2x00lib_request_firmware: Error - Failed to request Firmware.
[ 76.002332] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 86.736004] eth0: no IPv6 routers present
[ 148.960038] phy0 -> rt2x00lib_request_fi........
Thsi is very handy when doing your own kernel development.
-m specifies how much ram (in the example it is 768MB)
-kernel specifies the path to the kernel file
-net tap,ifname=tap1,script=no (the ifname=tap1 is what you need to change and setup manually).
*Run "tunctl -b" to create a tap device and use the one it gives you for ifname=
Enable networking to the outside like this:
*Note we assume that your bridge is br0 i........
Are you getting the same old error message even though your iptables settings for OpenVZ are correct?
iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
The reason is because in newer vzctl the old way of setting IPTABLES="" in vz.conf is completely deprecated (I spent some time fiddling wondering why my settings were correct but........
It is a permissions issue that is hard to fix.
All but one USB device is greyed out.
I am already a member of "vboxusers"
I have already enabled and disabled USB support for the guest.
I have already reinstalled the latest VBOx guest editions
If running as root it all works fine
Changing........
The solution is to run '/etc/init.d/vboxdrv setup' and sometimes happens when upgrading VBox and the kernel modules don't get upgraded with it. Sometimes the above doesn't work until you reboot because sometimes other unknown processes (even the file manager possibly) may be locking the old module from being unloaded.
Failed to open a session for the virtual machine XP.
The virtual machine 'XP' has terminated unexpectedly during startup with exit code 1.........
iptables -t nat -A PREROUTING -p tcp -m tcp -d 192.168.2.1/32 --dport 3389 -j DNAT --to-destination 192.168.5.2:3389
iptables v1.4.7: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
The above is often because you don't have the correct modules loaded on the hostnode or enabled for the container but in some cases it's actually a weird openvz setting.
Che........
2014-08-12T19:05:55-0400 vzctl : CT 391801 : Unable to start init, probably incorrect template
2014-08-12T19:05:55-0400 vzctl : CT 391801 : Container start failed
This was caused by trying to run a 64-bit template on a 32-bit kernel hostnode which is obviously impossible.
The solution is to use a 32-bit template or upgrade the hostnode to 64-bit.........
This is what fixed it:
[root@box13 ~]# dd if=/dev/zero of=/dev/md160 bs=512 count=500
Basically you need to wipe out more than just the 512 byte partition table so 512 bytes * 500 is more than enough to make DRBD happy and think the partition is now empty.
The reason this happens is because it gets confused when there is a previous partition with data on the device you are using.
root@box13 ~]# d........
I used the matching 8.3.13 utilities and it didn't work but strangely the newer 8.3.16 which makes DRBD complain works just fine.
GIT-hash: 83ca112086600faacab2f157bc5a9324f7bd7f77 build by root@sighted, 2012-10-09 12:47:51
0: cs:SyncSource ro:Secondary/Primary ds:UpToDate/Inconsistent A r-----
ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5236960
&am........
./configure
./configure: line 91: cd: /lib/modules/2.6.32-042stab084.25/build: No such file or directory
Error: kernel version not found.
Please make sure your kernel is configured.
dr-xr-xr-x. 4 root root 4096 Feb 21 06:13 ..
lrwxrwxrwx 1 root root 45 Feb 21 06:13 build -> ../../../usr/src/kernels/2.6.32-042stab084.25
drwxr-xr-x 2 root root 4096 Feb 12 20........
yum -y install wget
wget -P /etc/yum.repos.d/ http://ftp.openvz.org/openvz.repo
rpm --import http://ftp.openvz.org/RPM-GPG-Key-OpenVZ
yum -y install vzkernel vzctl
After that just reboot and you may also have to enable ip_forward in /etc/sysctl.conf........
nf_conntrack: table full, dropping packet
The above in some cases I've seen is a sign of a DOS attack or can occur if users are using services like torrenting, proxy, VPNetc... Do not take it lightly as the above can knock a server offline if the table becomes full and I've also seen full crashes and kernel panics shortly after.
........
kernel:[735188.961824] Kernel panic - not syncing: Fatal exception in interrupt
Write failed: Broken pipe
I'm not sure what is causing this and have never seen it on any server before.........
Kernel panic - not syncing: Attempted to kill init!
Pid: 1, comm: init Not tained: 3.2.51-3.el6.x86_64 #1
Call Trace:
panic+0x8c/0x1a2
forget_original_parent+0x34d/0x360
exit_notify+0x12/0x140
do_exit+0x1d8/0x400
do_group_exit_+0x50/0xc0
sys_exit_group+0x12/0x20
system_call_fastpath+0x16/0x1b
panic occurred, switching back to text console........
This server has been running for weeks without issue, it's currently only using 1 of 2 CPUs as it is running in the office as a test bed (mainly due to the handle 12 bay storage/great for testing HDDs). The errors below seem to mainly be from AMD CPUs, it's only happened a single time and in the days since Igot that error it hasn't occurrred.
Interestingly enough /proc/cpuinfo still shows all 4 cores of the CPU (Opteron 2373 Quadcore HE) and the functionality doesn't seem........
./configure
./configure: cannot locate gcc 3.x. please install it or specify with --qemu-cc
yum -y install gcc make
./configure
./configure: cannot locate gcc 3.x. please install it or specify with --qemu-cc
yum -y install compat-gcc-*
./configure
Error: Could not find alsa
Make sure to have the alsa libs and headers installed.
yum -y install alsa-lib-devel
./configure........
On the same OS with the same kernels basically I cannot boot FreeBSD installer, I believe the issue is the host CPU.
One host runs an Intel and works, while an Opteron 2373 does not work despite suggestions from this thread: http://149.20.54.209/showthread.php?t=36761
I've tried cpu options like "kvm64" "Opteron_G3" and none........
Linux box13. 2.6.32-042stab076.5 #1 SMP Mon Mar 18 20:41:34 MSK 2013 x86_64 x86_64 x86_64 GNU/Linux
even setting privvmpages to a specific setting DOES not affect "free -m" in containers.
This is probably a kernel issue
23:36:29 up 159 days, 7:12, 4 users, load average: 0.42, 0.44, 0.33
[root@box13 ~]# free -m
total&n........
Sep 26 16:56:21 box kernel: 00 00 00 00 00 00 00 00
Sep 26 16:56:21 box kernel: [37007.155690] d_alias libdl-2.12.so d_count=9 d_flags=8
Sep 26 16:56:21 box kernel: [37007.155697] 09 00 00 00 08 00 00 00 9f 05 9f 05 00 00 00 00 c0 71 1d 18 04 88 ff ff 00 00 00 00 00 00 00 00 a0 7e 48 00 00 c9 ff ff 78 a9 21 18 04 88 ff ff 3a 7b fa 4e 0d 00 00 00 98 5c 2d 18 04 88 ff ff 18 5c 2d 18 04 88 ff ff 18 5c 2d 18 04 88 ff ff 00 01 10 00 00 00 ad de 00 02 20 00 00 00 ad de f8........
I flashed an LSI Logic firmware to it and it broke the BIOS (cannot do Ctrl+R) for booting purposes but allows other functionality to work normally.
I tried downgrading to a Dell firmware for Perc 6i but it won't work, not even with MegaCli
wget http://downloads.dell.com/FOLDER00416606M/1/SAS-RAID_Firmware_W83M2_LN32_6.3.1-0003_A14.BIN
--2013-08-26 12:53:39-- http://downloads.dell.com/FOLDER00416606M/1/SAS-RAID_Firmware_W83M2_LN32_6.3.1-0003_A14.BIN
Resolvi........
package kernel-xen-2.6.18-274.7.1.el5.x86_64 is intended for a x86_64 architecture
Linux etc 2.6.18-274.7.1.el5xen #1 SMP Thu Oct 20 17:06:34 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
As you can see above architecture and kernel is 64-bit but I had to force it to install using "--ignorearch"
Solution
#rpm --ignorearch -ivh kernel-xen-2.6.18-274.7.1.el5.x86_64.rpm
Preparing...&nb........
kernel: EDAC MC0: CE page 0x0, offset 0x0, grain 1073741824, syndrome 0x1a, row 2, channel 0, label "": i3200 CE
I believe this is a hardware issue, it's usually bad RAM, incompatible RAM or bad timing or even a motherboard/RAM controller.........
Jun 12 10:30:53 kernel: [724514.291670] EXT4-fs error (device md20): ext4_add_entry: bad entry in directory #2552670: rec_len % 4 != 0 - offset=216, inode=2553603, rec_len=94, name_len=84
Jun 12 10:30:53 kernel: [724514.292400] EXT4-fs error (device md20): ext4_add_entry: bad entry in directory #2552670: rec_len % 4 != 0 - offset=216, inode=2553603, rec_len=94, name_len=84
This happened when an unprivileged user was backing up a Windows filesystem, once they ha........
Another new drive bad from the start:
Jun 2 15:14:18 one-desktop kernel: [15895.386779] ata2.00: exception Emask 0x50 SAct 0x1 SErr 0x280900 action 0x6 frozen
Jun 2 15:14:18 one-desktop kernel: [15895.386782] ata2.00: irq_stat 0x08000000, interface fatal error
Jun 2 15:14:18 one-desktop kernel: [15895.386784] ata2: SError: { UnrecovData HostInt 10B8B BadCRC }
Jun 2 15:14:18 one-desktop kernel: [15895.386788] ata2.00: cmd 60/0........
If you move your hard drive(s) around to other computers/servers, you'll find that your eth0 keeps getting higher, the first time it will become eth1 and then eth2 etc and even higher if your server has dual or quad NICs. The reason is that udevd basically assigns eth0 tot he first NIC it finds and remembers it, if it encounters a NIC with a differentMAC, it assigns it one higher (eg. eth1).
See the example below, I have eth2 now so how doI fix it?........
Client Log
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 192.168.1.253 [192.168.1.253] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type 1
debug1: identity file /root/.ssh/id_d........
Kernel panic - not syncing: Attempted to kill init!
Pid: 1,comm: init Tained: G I------------- 2.6.32-358.el6.x86_64 #1
Call Trace:
[] ? panic+0xa0/0x16f
[] ? do_exit+0x862/0x870
[] ? fput+0x25/0x30
[] ? do_group_exit+0x58/0xd0
[] ? sys_exit_........
-bash-3.1# shutdown -rn now
Connection to localhost closed by remote host.
Connection to localhost closed.
Sometimes I work with embedded systems/custom kernels without any of the fancy init scripts and other common Linux basics that most would expect. This means that often the "reboot" command (which uses an init script) will never work, not only that but it will hang the server and a manual power cycle or reboo........
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
For whatever reason it seems the r8169 driver that ships and has shipped with most Linux distros for years is still flawed and does not work properly on these cards, causing 100mbit connectivity when it should be 1gbit and even worse, causing random network dropouts. The r8169 driver in Linux kernels is simply not meant to be used on th........
There are 3 pieces that are required to restore and make it work (of course consider if any kernel modules need to re-enabled and if you need to change the IPs):
Copy the vz/private/VEID directory to /vz/private
Copy the /etc/vz/conf/VEID.conf to /etc/vz/conf/
mkdir /vz/root/VEID
After that you should be able to see the VE in vzlist -a
You should then be able to start it normally.........
This pops up when connecting the phone and it doesn't seem to charge. The phone keeps showing a status message every few seconds "Connected as a media device".
It's ridiculous why this phone doesn't just default as a simple USB Mass storage device.
Here's what I see in /var/log/messages:
Jan 30 18:51:27 QuadCoreAM2 kernel: [18038228.144046] usb 1-3: new high speed USB device using ehci_hcd and address 24
Jan 30 18:51:28 QuadCoreAM2 ke........
This seems to be a verified bug on KVM with no solution. I wasn't able to get through the installer with Ubuntu 12.04, it would crash while "configuring apt". I was able to install it with Ubuntu 12.10 but it crashes randomly at times.
This happens with the latest Centos 6.3 kernel and KVM package, I even compiled the latest version from the KVM website and used that, but the results are still the same.
Here's some links to discussion about the bugs:........
This booting error is because the Xen PV guest image uses the Xen kernel, this is not compatible with anything but a host running a Xen kernel.
I did a kpartx -av virtual.img and then it created some partitions that showed up in fdisk.
I mounted it and did a chroot into it and removed the xen kernel and installed a normal kernel but Xen still shows the same kernel in Grub (only the Xen one).
This is strange but it seems like this Xen PV guest has some sort of hidden or........
Inever started these processes but they are from a custom based bootable Linux I've made and I've never seen this behavior on other machines or even with the same machine using different kernels. These processes seemed to spawn on their own and I have no idea why and even worse why the CPU usage is so high?
Here's the output from top:
907 extaudit 30 10 0 0 0 R 90.7 0.0........
This is something I often setup for clients because it's very helpful for people in datacenters, this allows custom OS installs on demand, you can customize it more by using kickstart etc.. but here's a base I use before customizing more:
This little script below will install everything you need to get booting by PXE Linux.
It also assumes you set a local IP (be sure not to overwrite your existing IP) on eth0:0 (note the :0) as 192.168.1.10 and it........
For whatever reason the current OpenVZ yum repo file enables the RHEL6 version of OpenVZ, why is this bad? Because if you're running Centos 5 it still defaults to using the kernel from RHEL6 which won't work on RHEL5/Centos 5.
Ionly realized this after wondering why I couldn't boot into OpenVZ that it was using one meant for RHEL6.
To fix the problem you have to edit /etc/yum.repos.d/openvz.repo and disable the "[openvz-kernel-rhel6]" section by changing........
This is so handy, especially if you need things like old kernels etc..., this is the main and practically only place you'll ever find what you need.
http://vault.centos.org........
Error: detected vswap CT config but kernel does not support vswap
This means either old kernel or bad config (physpages NOT set to 0:unlimited)
Solution
vzctl set $veid --physpages 0:unlimited --save........
I've encountered this problem before and I believe it may affect other drivers (I could test but I don't have time). This was happening on my custom Linux system with the pcnet32 driver.
pcnet32: eth0: transmit timed out, status 97fb, resetting (and some other kernel module tracing in dmesg)
Basically it means the card is connected (it shows connected in full duplex etc.. and recognized if the cable is disconnected too) but no packets can be sent or received........
I'm running Ubuntu 10.10 with Asus NVIDIA GT430
2.6.35-32-generic-pae #65-Ubuntu SMP Tue Jan 24 14:06:16 UTC 2012 i686 GNU/Linux
Nvidia binary driver: 260.19.06
The screen sometimes completely freezes and locks up or everything starts going very slow:
[1903398.100007] NVRM: os_schedule: Attempted to yield the CPU while in atomic or interrupt context
[1903402.373210] NVRM: Xid (0001:00): 53, CMDre 00000000 00000080 00000000 00000005 00........
I dread updating the kernel and rebooting to find the Ubuntu graphics aren't working and you have to manually intervene. This is usually because Ubuntu for whatever reason didn't update the drivers you need (eg. the manually compiled Nvidia Kernel driver that MUST be recompiled for each and every kernel update unfortunately).
The most common reason may be that "linux-source" hasn't been installed automatically on my system. I tried to manually reinstall the........
I really am a Linux fan but my comments here may not show it. Although I'm quite familiar with Linux CLI to administer servers, I find Linux GUI OS's like Ubuntu at times very clunky.
This is partially because there's no such thing as a "self-made" Linux from scratch where the UIwas designed by a single team. Linux is made up of several different projects that are generally completely separate and this lack of integratiion is a key issue that makes things f........
This is one in a series of weird things whichIthought was motherboard related (I RMA'd the motherboard), the RAM tests fine with memtest86 and I used badblocks on both RAID 1 members with no errors and smartctl is happy with them.
Basically the array crashes the kernel a lot and has issues when writing.
[112322.723465] md0: rw=0, want=14958668696, limit=1887460480
[112322.731077] attempt to access beyond end of device
[112322.731087] md........
These were caused by a bad stick of Corsair RAM
[] free_hot_cold_page+0xfc/0x150
[] __pagevec_free+0x14/0x1a
[] release_pages+0x127/0x12f
[] __pagevec_release+0x15/0x1d
[] __invalid_mapping_pages+0x120/0x156
[........
ifup eth0
SIOCSIFFLAGS: Cannot allocate memory
Failed to bring up eth0
This is on a Centos 5.5 machine with OpenVZ kernel 2.6.18-238.12.1.el5.028stab091.1PAE, I updated 3 systems with the same hardware to the same kernel and for some reason the network didn't come back.
This only happened once the first time I booted into the new kernel and hasn't happened again but this is a serious issue for those running systems from remote locations such as a datacente........
I had a system running a 128MB live CD image with 2.8 gigs of available RAM and the OOM kernel killer went crazy when using dd for more than 8 minutes and kept killing everything. I've read that this is due to a low-memory issue and paging in the kernel and 32-bit systems with lots of RAM.
I even enabled swapspace on my LiveCD and the issue happened 25 minutes into dd rather than 8 minutes, so what gives?
Also no swap space was ever used!
cat /proc/s........
I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem:
We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........
CPT ERR: cc4c0800,28000 :Unknown image version: 304. Can't restore.
This happens when you live migrate between OpenVZ servers with different kernels running, at least significantly different by date.
There is no solution except to make sure you're running the same kernels on all machines, or at least not kernels that are much older or different (this is just a guess though, you should ensure all kernels are the same).........
Warning: Unable to open /dev/fd0 read-write (Read-only file system). /dev/fd0 has been opened read-only.
That's a very annoying error, it's simply because Centos for some reason thinks it's wise to load the "floppy" kernel module, who has a floppy drive? I haven't seen or used a floppy for over 12 years!
It's more than just annoying, if you probe the drives attached to your system, eg. with grub or partprobe, it keeps trying to locate a flopp........
It's weird because I have a nearly identical box and setup and I can update the ovzkernel-PAE* just fine but on this box it doesn't work.
I only get this error with the openvz.repo and not others such as Centos-Base.repo
With my other server it works normally:
================
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package ovzkernel-PAE.i686 0:2.6.18-238.12.1.el5.0........
This assumes that you've at least created the correct partition for your DRBD already.
Notice that I am "diskless", that's because either your DRBD partition doesn't exist/has been renamed (eg. sdb becomes sda when sdb dies and you reboot) or because that drive is really actually dead/gone.
*If you need to permanently change the partition/device for your resource be sure to edit /etc/drbd.conf on both hosts and reload the config.
(replace r0 with........
I thought only a faster CPUand SSDwould help but I already have a Quad-Core CPU and it wasn't being maxed out. The actual tests were performed on an AMD-V enabled 128MB dual core VMWare container though.
There is a flag that can be passed to make in order to start multiple threads, by specifying 4 threads I was able to reduce the whole kernel compilation time from scratch by about 50%! (65minutes vs 31minutes!). *Yes I did do a make clean before each co........
In file included from drivers/block/cciss.c:1015:
include/asm-generic/pci-dma-compat.h: In function `cmd_special_free':
drivers/block/cciss.c:196: sorry, unimplemented: inlining failed in call to 'cciss_tag_discard_error_bits': function body not available
include/asm-generic/pci-dma-compat.h:25: sorry, unimplemented: called from here
make[2]: *** [drivers/block/cciss.o] Error 1
make[1]: *** [drivers/block] Error 2
make: *** [drivers] Error 2........
This happened during a RAID array check:
SMART says both drives pass the test, but I'm doing a long test on them and hopefully this is not a hardware error.
Apr 3 04:22:01 remote kernel: md: syncing RAID array md2
Apr 3 04:22:01 remote kernel: md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc.
Apr 3 04:22:01 remote kernel: md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reconstruction.
Apr........
My Samsung drive failed on me, at first I thought it was the enclosure but a direct SATA connection causes the same problems for discs that are inserted. It will work fine for a few minutes but then starts spewing the errors below.
I've never been a fan of Korean made optical drives and have always had trouble with them. The problem is that I don't believe NEC and Lite-ON make drives anymore, and I considered them the leaders.
Apr 7 11:58:48 bo........
high IO wait
424 root 39 19 1900 848 552 D 0.0 0.0 0:00.91 updatedb
root 424 0.0 0.0 1900 848 ? DN Mar11 0:00 /usr/bin/updatedb -f sysfs?rootfs?bdev?proc?cpuset?binfmt_misc?debugfs?sockfs?usbfs?pipefs?anon_inodefs?futexfs?tmpfs?inotifyfs?eventp........
Failed to open a session for the virtual machine XP.
AMD-V is being used by another hypervisor. (VERR_SVM_IN_USE).
VirtualBox can't enable the AMD-V extension. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_SVM_IN_USE)
Solution - Unload KVM module (you can't use two hardware virtualization suites at once)
sudo rmmod kvm_amd kvm........
kernel 2.6.27.54
Fusion MPT base driver 3.04.07
Copyright (c) 1999-2008 LSI Corporation
Fusion MPT SPI Host driver 3.04.07
mptbase: ioc0: Initiating bringup
mptbase: ioc0: WARNING - Unexpected doorbell active!
mptbase: ioc0: ERROR - Doorbell ACK timeout (count=4999), IntStatus=80000001!
mptbase: ioc0: ERROR - Diagnostic reset FAILED! (102h)
mptbase: ioc0: WARNING - NOT READY!
mptbase: ioc0: ERROR - didn't initialize proper........
I think this will be useful to others because I have a server that kept crashing mysteriously during intense disk usage/RAID checks. It would only crash during the weekly RAID integrity check.
ThenI noticed during a reboot that not all CPUs were being brought up, as a result this actually creates much higher temperatures with the output I got from sensors, just booting the system produced higher than normal temperatures.
You can imagine that a full blown RAID check........
Jan 16 04:02:03 centosbox syslogd 1.4.1: restart.
Jan 16 04:07:34 centosbox kernel: INFO: task updatedb:20771 blocked for more than 300 seconds.
Jan 16 04:07:34 centosbox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Jan 16 04:07:34 centosbox kernel: updatedb D F78BE050 6476 20771 20766&n........
CPU/Kernel/MB/RAID problem?
Jan 5 12:45:05 testbox kernel: [653298.890004] BUG: soft lockup - CPU#0 stuck for 61s! [hal-acl-tool:4168]
Jan 5 12:45:05 testbox kernel: [653298.890005] Modules linked in: vmnet vmci vmmon binfmt_misc drbd video output input_polldev ocfs2_stackglue ocfs2_dlmfs ocfs2_dlm ocfs2_nodemanager configfs k8temp hwmon_vid lp snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi........
This made me nervous but it's clearly a cronjob based on the messages log that happens every Sunday at about 4:22.
I actually can't find any evidence of it in cron.d cron.daily but it is there somewhere obviously.
What I don't get is why doesn't this cronjob do a datacheck like Ubuntu's cronscript does? When you unnecessarily rebuild the array you lose your redundancy during that point which makes your data extremely vulnerable.
*Update I did a grep of &q........
I've only used it on Centos, soI thought I'd make a quick Debian guide:
Install the DRBD Package
apt-get install drbd8-utils
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libswfdec-0.8-0
Use 'apt-get autoremove' to remove them.
The following........
yum exits in the middle
The problem is this VPS seems to be an OpenVZ template from HyperVM. The only way to make it work was to disable i386 packages since this was an x64 kernel. That shouldn't be necessary but it was the only way to make yum stop quitting after the first package or two. I couldn't find any issue by checking the logs either.
echo y|yum install vim-minimal telnet expect jwhois net-tools slocate iptables elinks gawk
L........
Nov 29 20:17:58 ubuntu kernel: [ 1157.180789] md: md1 stopped.
Nov 29 20:17:58 ubuntu kernel: [ 1157.180829] md0: unknown partition table
filesystem not responding/reading properly with du or rsync (this needed an fsck).
[ 2571.489217] EXT3-fs error (device md2): ext3_lookup: deleted inode referenced: 35923106
[ 2571.942299] EXT3-fs error (device md2): ext3_lookup: deleted inode referenced: 35923110
[ 2571.9568........
ping test.com
connect: No buffer space available
/var/log/messages
Oct 18 12:21:03 vps kernel: printk: 177 messages suppressed.
Oct 18 12:21:03 vps kernel: Neighbour table overflow.
Solution in /etc/sysctl.conf:
net.ipv4.neigh.default.gc_thresh1 = 4096
net.ipv4.neigh.default.gc_thresh2 = 8192
net.ipv4.neigh.default.gc_thresh3 = 8192
net.ipv4.neigh.default.base_reachab........
had trouble trying to revert Ubuntu 10.04 LTS from grub2, won't boot mdraid and did not even install mdadm during the installation!
I have tried moving back to GRUB 0.97
backed up original /boot and then copied /boot from an old Debian install. Modified device.map and menu.lst and put the appropriate kernels and initrd for Ubuntu back in /boot
I ran grub:
root (hd0,1)
grub> setup (hd0)
Checking if "/boot/grub/stage1........
2.6.35.2 stuck on the following:
msgmni has been set to 1466
request_module: run away loop modprobe char-major-5-1
I don't know the fix for it, but it is an old bug that has reappeared.........
service vz start
Starting OpenVZ: failed to load module vzmon [FAILED]
vzmon: Unknown symbol ve_snmp_proc_init
vzmon: Unknown symbol addrconf_sysctl_free
vzmon: Unknown symbol ve_ndisc_init
vzmon: Unknown symbol addrconf_ifdown
vzmon: Unknown symbol ip6_frag_cleanup
vzmon: Unknown symbol fini_ve_route6
........
cd /etc/yum.repos.d
wget http://download.openvz.org/openvz.repo
rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ
yum install ovz-kernel-PAE
Now remember to set /etc/sysctl.conf to "net.ipv4.ip_forward = 1"
You can apply the change immediately by running sysctl -w net.ipv4.ip_forward = 1 but remember that you still have to set sysctl.conf
sysctl -p will load and apply any changes to s........
Remember to replace "eth0" with your NIC device although usually it will be eth0.
Replace 192.168.1.1 with your default gateway, remember you can also add multiple gateways by adding a second/different default gateway.
route
Kernel IP routing table
Destination Gateway Genmask&nb........
wget http://download.virtualbox.org/virtualbox/3.2.8/VirtualBox-3.2-3.2.8_64453_rhel5-1.i386.rpm
rpm -i http://download.virtualbox.org/virtualbox/3.2.8/VirtualBox-3.2-3.2.8_64453_rhel5-1.i386.rpm
error: Failed dependencies:
libGLU.so.1 is needed by VirtualBox-3.2-3.2.8_64453_rhel5-1.i386
libSDL-1.2.so.0 is needed by VirtualBox-3.2-3.2.8_64453_rhel5-1.i386
libXmu.so.6 is needed b........
This happens on some systems due to a video issue with Intel Videocards, after you see the kernel load you may see almost immediately that you get a black screen.
The following kernel parameters usually solve it:
nomodeset i915.modeset=0 xforcevesa
some people just use "nomodeset" and others use "i915.modeset=0". I think nomodeset may also do the same for each video driver so it may imply i915.modeset=0 anyway but I am not sure.........
You'll see the following and the boot process will freeze:
io scheduler noop registered
io scheduler anticipatory registered
io scheduler deadline registered
io scheduler cfq registered (default)
I have struggled with this issue on vari........
NET: Registered protocol family 2
The above is the last thing that I ever saw, I tried pci=routeirq etc.. and it wouldn't work.
The solution is to enable IOAPIC in the VBOX Settings
Just enable "IOAPIC" in the settings for your Centos Guest and you'll find the kernel boots just fine. I wonder if a physical system might stall in this same way if the BIOS has IOAPIC disabled which many people do as a troubleshooting method.
........
I am a huge fan of Linux and the idea of OpenSource but I've said it many times, there are still hurdles in today in 2010 for Linux as a Desktop. Linux is still intended for servers at its very core. This can be changed succesfully though, as Apple has shown us with Mac OS X based on FreeBSD.
Half of the issue is lack of driver support and the other half is the Linux Kernel and Window Manages, KDE and GNome still both don't cut it (but they're getting closer).
I'll........
This error is annoying, in a Virtuozzo KB entry about this ip tables nat problem they say the kernel needs to be ugpraded:
Symptoms
The node runs 2.6.18-x kernel older than 2.6.18-028stab053.10.
NAT module does not work in container, you get "can't initialize iptables table 'nat'" error:
# iptables -t nat........
This is obviously a bug in the r8169 kernel module and it seems to affect a lot of people. I upgraded to the latest kernel and hope this won't happen anymore, as it is a very serious error. This is especially serious for those who are running servers with this chipset, who can afford for the NIC to randomly go off-line for no apparent reason?
[655548.189113] type=1505 audit(1277067560.902:5): operation="profile_load" name="/usr/bin/freshclam&q........
This is a great way to use your ftp server space, for example on your web hosting account (althoughI believe many hosts don't allow storage like this), but if you have a VPS/Dedicated Server etc.., this would be perfect. Imagine how easy it is to work with an ftp account that you can just mount as a normal partition or directory in Linux, it would be great for backups etc..
Name
curlftpfs - mount a ftp host as a local directory
Synopsis........
I'm using Ubuntu 8.04 but anyone using older kernels will find this may apply to them. My Intel graphics are very slow with the default Xorg settings but by using "EXA" acceleration, scrolling down windows of text becomes pretty snappy.
Just edit /etc/X11/xorg.conf
Section "Device"
Identifier "Configured Video Device"
&nb........
I successfully created a single RAID 1 partition which includes /boot inside it and my root directory through the Debian installer. It said GRUB installed successfully but when I try booting the OS it seems GRUB can't read anything.
When trying to boot from GRUB
GRUB Loading stage 1.5.
GRUB loading, please wait...
Error 2
I get "Error 2" when trying to boot Debian. I also notice from a LiveCD that........
I installed 5.5 with a 300GB RAID 1 partition (boot is also on this partition). It booted up fine the first few times until after I used a Live CD and accessed the array, and it became named /dev/md127 for some reason.
Now whenI boot into CentOS I get a kernel panic and different errors, once I got "invalid superblock", even though the array is fine (it didn't happen again, probably because I was sure to dismount and stop the mdadm array properly).
Here's what........
I'm not impressed with this motherboard, I was impressed with my Gigabyte AM3 board which seems to work flawlessly.
Everyone knows that the firmware is flawed, even though I have the F6, it still seems that the system doesn't reset properly or quickly enough.
Another HUGE problem is that in most Linux kernels the NIC won't work (if you try 10 times by rebooting it might). I also notice that you need to power down for it to work.
This board does not seem very com........
This was unbelievable how much the Xen kernel slows things down, keep in mind both tests were done on the hostnode, one was with the Openvz-Xen hybrid kernel and the other was just OpenVZ. You can see the performance difference is nearly 300% better when not using the Xen kernel.
OpenVZ-Xen Kernel Test Results (I was wondering what was wrong/so slow with my Core i5!)
# # # # # #&n........
CC drivers/message/fusion/mptsas.o
drivers/message/fusion/mptsas.c: In function `mptsas_port_delete':
drivers/message/fusion/mptsas.c:106: sorry, unimplemented: inlining failed in call to 'mptsas_set_rphy': function body not available
drivers/message/fusion/mptsas.c:462: sorry, unimplemented: called from here
make[3]: *** [drivers/message/fusion/mptsas.o] Error 1
make[2]: *** [drivers/message/fusion] Error 2
mak........
Apr 30 17:07:07 localhost kernel: [12265558.582378] r8169: eth0: link up
Apr 30 17:07:07 localhost NetworkManager: (eth0): carrier now ON (device state 1)
Apr 30 17:07:08 localhost kernel: [12265559.237961] r8169: eth0: link down
Apr 30 17:07:08 localhost NetworkManager: (eth0): carrier now OFF (device state 1)
Apr 30 17:07:11 localhost NetworkManager: (eth0): carrier now ON (device state 1)
Apr........
This drive is clearly on the way out, the Kernel knows it but I'm surprised that SMART is not concerned. I didn't blame Seagate for their past issues until now. This hard drive has hardly been used and has not even been powered on for a year according to SMART.
Home page is http://smartmontools.sourceforge.net/
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.11
Device........
GRUB Boot FreeBSD[code:1:a7050277b7]title FreeBSD 6.0
root (hd0,2,a)
kernel /boot/loader[/code:1:a7050277b7]
Just insert the above code into GRUB's [b:a7050277b7]menu.lst[/b:a7050277b7] and make sure you set the root path correctly.
[quote:a7050277b7]Let's quickly explain what the root (hd0,2,a) means:
*hd0 stands for the primary master drive
*2 stands for partition 3
*a stands for the........
How to extract files from RPM & SRPM filesmkdir any_directory
cd any_directory
rpm2cpio /location/of/package.src.rpm | cpio -d -i
This will extract all files, I find it especially useful if you want to manually compile the kernel source from the srpm........
Centos 4.3 x64 & VMWare Server Beta[code:1:6d0b2c8c2f]
The correct version of one or more libraries needed to run VMware Server may be
missing. This is the output of ldd /usr/bin/vmware:
linux-gate.so.1 => (0xffffe000)
libm.so.6 => /lib/tls/libm.so.6 (0xf7fbd000)
libdl.so.2 => /lib/libdl.so.2 (0xf7fb9000)
libpthread.so.0 => /lib/tls/libpthread.so.0 (0xf7fa7000)
libX11.so.6 => not f........
Upgrade Release Kernel TipsThis is for CentOS 3.1 to 3.8 but the methodology will apply everywhere.
I ran into a problem first of all with a non-booting system after running
#yum update centos-release
It took me to 3.8 and upgraded all the other packages [b:7e931c835d]BUT[/b:7e931c835d]
because of some stupid flags enabled in /etc/yum.conf the KERNEL WASN'T UPGRADED SO AFTER BOOTING, WELL IT DIDN'T BOOT OF COURSE :)
H........
Updated to Version 3.8 and can't loginSSHD accepts my password but then hangs at "Last login: Wed Sep 13 21:30:02 2006 from"
This occurred during a yum update after upgrading my release, installing the new kernel and rebooting.
I got kicked out of sshd after seeing the following during yum update:
telnet 100 % done 85/476
tux 100 % done 86/476
ntsysv 100 % done 87/476
rpmdb-redhat 94 % done 88/476........
Upgrade FreeBSD/usr/source/
make build world, make build kernel, make install kernel, make install world
I'll test this later on and see if it works!Here is a good guide to update FreeBSD:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html........
CVSUp the Easy WayIf you're reading this you probably have never used CVSUp or don't know how.
CVSUp can be used for two things or just one if you prefer.
*Keeping your kernel up to date
*Keeping your port list up to date
Start by editing the following file in:
[b:76928b387d]vi /usr/share/examples/cvsup/cvs-upfile[/b:76928b387d]
It can be quite overwhelming with all the crazy options.
Basically there are only 3........
*This is a bug with initramfs support, all kernels after around 2.6.27.54 suffer from this problem.
If you try to include initramfs into your kernel (I mean actually building your binaries into the kernel) this will always happen. Obviously some code has changed in recent kernels that is present in all new kernels, it makes it impossible to boot
I've tried the latest 2.6.32, 2.6.33, 2.6.34, 2.6.35, 2.6.36, 2.6.37, 2.6.38 kernels and they all do this. I found one bug re........
Linux Kernel v2.6.30.3
102220 blocks
CHK include/linux/version.h
CHK include/linux/utsrelease.h
SYMLINK include/asm -> include/asm-x86
CALL scripts/checksyscalls.sh
CHK include/linux/compile.h
CC drivers/net/igb/igb_main.o
drivers/net/igb/igb_main.c: In function `igb_up':........
top - 09:34:12 up 2 days, 20:57, 2 users, load average: 1.83, 1.99, 2.03
Tasks: 59 total, 2 running, 57 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.3%us, 0.0%sy, 0.0%ni, 0.0%id, 99.7%wa, 0.0%hi, 0.0%si, 0.0%st
That 99.7% wa is iowait, it means the server is waiting for a process to complete an IOoperation or in plain English, there is a delay in........
I've tried to find a good sensible solution to cluster with and each technology has it's pros and cons and there is no perfect solution and I've found a lot of "exaggerations" in the applications, benefits and performance of these different filesystems.
DRBD
I first started off with DRBD and Ihave to say it does live up to the hype, is quite reliable (although it can be annoying to match up the kernel module and user applications since they must match and whe........
Inever saved any of the logs, but basically no matter what OS (Linux)I used, I could not get my 1000GB hard drive to work (Seagate SATA). The BIOS recognizes the drive and fdisk -l shows the hard drive as it should.
The tricky thing is that different OS's will give you different results, but don't be fooled. You can't use these larger drives for long. Iwas getting all kinds of seek/IOerrors and also messages that the port could not be read.........
For some reason Ikeep getting this error when trying to run a sudo command eg:
sudo -u someuser somecommand
sudo: Error dropping capabilities, aborting
My version of sudo is:sudo-1.6.9p17-3.el5_3.1 and I've heard that version 1.7 fixes everything. The only thing is yum does not think sudo has any update. Iguess the new version has not been committed to the RPM repository yet.
This is really a huge and ann........
As much of a computer nerd as Iam, I'm usually a late adopter to technology for a few reasons. Ifeel most new hyped technologies and electronics are mainly fads, and I'm also cheap.
Adopting later means you avoid the bugs, kinks and most importantly pay the lowest price, that's me being cheap again :)
I never read much about the iPhone but Isaw all the hype around it and until recently I wasn't a big fan of anything Apple until a few years ago I realize........
When trying to even cd or ls the mounted OCFS2 partition it crashes. Ithink this is a combination of VMWare Server's problem and the way I mounted and symlinked to it.
More than anything this shows the problem and lack of forsight with VMWare, but also that OCFS2 is easily crashed if you do strange things.
Output of /var/log/messages for OCFS2
Apr 10 15:57:45 localhost kernel: [84331.691258] Modules linked in: vmnet vmci vmmon ocfs2_stac........
There's a lot of information and guides on OCFS2 for RHELand Centos Linux but the package setup and configuration is slightly different and this has thrown some people off.
Installing OC2FS
You should install the following packages to get started:
apt-get install ocfs2-tools ocfs2console
Configure OC2FS
In RHEL/Centos the main configuration file is located in /etc/sysconfig/o2cb
However in Debian based Linux it is located........