Disk /dev/sdb: 15.22 GiB, 16336814080 bytes, 31907840 sectors
Disk model: SD/MMC
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000
The fdisk output is above and below is the error you may get when trying to use the d........
Since newer versions of Ubuntu like 20, you will find there is no longer dynagen and that the dynamips provided is faulty and will segfault each time:
Cisco Router Simulation Platform (version 0.2.14-amd64/Linux stable)
Copyright (c) 2005-2011 Christophe Fillot.
Build date: Apr 3 2018 12:20:29
Local UUID: 3c1c0b7f-2fab-4fda-b40b-74841d1bcfe0
Instance ID set to 1.
netio_tap_create: unable to open TAP device tap1 (No such fi........
Use gs or ghostscript as below, specify the output file and also the input file.
In the example below the output file is "outputfile-resized.pdf" and the input file is "original-pdf.pdf". Change the input file to the name of your pdf
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/prepress -dNOPAUSE -dQUIET -dBATCH -sOutputFile=outputfile-resized.pdf original-pdf.pdf
For........
If you have ever seen a system where terminal in the GUI closes instantly and/or you cannot SSH to the server/machine.
mount -t devtmpfs none /dev
mount -t devpts none /dev/pts........
This is mainly for if you've done something silly like trying to clone a Live, running VM image. In this example, the VM initially finds grub and tries to boot but is kicked straight into initramfs rescue mode/busybox right after this.
If you've done this "silly" thing, you could have dataloss but a lot of times just using fsck will fix it as you are guaranteed at best to have some corruption and inconsistencies in the filesystem. My theory is that some files wer........
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"........
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........
Sometimes users take their removal drives and unplug and replug them to test what happens during the failure of a disk. However, this breaks things quite badly due to the /dev/mapper in LUKS not coming back online due to it not being closed.
In other words, generally with non-encrypted drives the process is smooth but when encrypted you may want to follow a strategy like this:
We can see below that both disks are unavailable as they were physically remov........
Have you ever tried mounting a partition that you exists but you get this error?
mount: /mnt: can't read superblock on /dev/sda1.
The superblock in this example was bad because the physical disk had corruption and bad blocks/sectors. However, the data was generally accessible and you can always try this trick below (with caution and no warranty).
This is specifically for filesystems that place superblocks in multiple locations, which........
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........
A lot of companies are unsure which solution to choose and many may not be aware of Docker Swarm as an alternative to Kubernetes. One thing that many Sysadmins find is that Docker Swarm is simply easier, quicker to setup and maintain by far than Kubernetes.........
First we need a few extra packages:
apt update
apt install -y adduser libfontconfig1 musl sudo
wget https://dl.grafana.com/enterprise/release/grafana-enterprise_10.3.1_amd64.deb
Install / Enable Grafana
dpkg -i grafana-enterprise_10.3.1_amd64.deb
dpkg -i grafana-enterprise_10.3.1_amd64.deb
(Reading database ... 44309 files and directories currently installed.)
Preparin........
Step 1.) Upgrade to Debian 11 first
The process to go to Debian 12 is not as smooth as 11, when trying to upgrade from Debian 10. In fact, it doesn't work directly, so you'll first need to follow this guide to update to Debian 11, reboot and come back here if successful.
Step 2.) Update sources.list
Update your /etc/apt/sources.list like this:
deb http://........
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........
The issue is that Docker images are stripped down, so many tools and even python3 is missing, so you'll have to build or update the actual image yourself.
I assume you have started an image with something like this and that you have the Nvidia Toolkit installed (assuming you are using GPUs). If you're not using nvidia just remove --runtime=nvidia --gpus all.
docker run -it --runtime=nvidia --gpus all ubuntu bash
These works for most images li........
Welcome to our in-depth guide on configuring NVIDIA GPUs with Docker on Ubuntu. This post is tailored for developers, data scientists, and IT professionals who are looking to leverage the power of NVIDIA's GPU acceleration within Docker containers.
Whether you're working on machine lea........
This does not seem to be officially documented but makes sense that an overlay on an overlay does not work and is considered an unsupported filesystem as is even NTFS . Some admins/organizations try to use ecyptfs as a simple solution to encrypt the contents of Docker. Instead, you could probably........
Just in case, it is reocmmended to backup the original contents of the directory (especially your home dir) before proceeding.
Setup ecryptfs
Run this command: ecryptfs-setup-private
It will ask you for your login password, this is so that when you login, everything is automatically decrypted by using a passphrase that is wrapped with your login.
You can hit enter and leave things blank for an autogenerated passphrase (for mounting) or you can en........
In a lot of distros like Debian, ecryptfs will mount itself in /home/yourusername/Private
This is controlled by Private.mnt which may contain the mount path like this:
/home/yourusername/Private
Change the default mount location of ecryptfs by modifying this file:
home/.ecryptfs/yourusername/.ecryptfs/Private.mnt
After you unmount and relogin, you should find ecryptfs is now mo........
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........
haproxy is one of the best known and widely used Open Source load balancers out there and a strong competitor to nginx.
haproxy is used by many large sites per Wikipedia:
HAProxy is used by a number of high-profile websites including GoDaddy, GitHub,........
If you are installing ta-lib for Python and get this error then you can normally solve it by manually getting the ta-lib source files and compiling.
tar -zxvf ta-lib-0.4.0-src.tar.gz
cd ta-lib;./configure;make;make install
Collecting ta-lib
Downloading https://files.pythonhosted.org/packages/39/6f/6acaee2eac6afb2cc6a2adcb294080577f9983fbd2726395b9047c4e13ec/TA-Lib-0.4.26.tar.gz (272kB)
&nbs........
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........
In this example we install debian 10 with --variant=minbase which gives us a minimal/tiny install. Don't use variant if you want the full size install.
mkdir /tmp/deb10files
debootstrap --variant=minbase buster /tmp/deb10files/
Did you get an error?
debootstrap --variant=minbase buster /home/theuser/VMs/deb10files/
You'll get this error if you make a directory in your home........
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........
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........
Docker adds iptables rules that break a lot of things including MASQUERADE or anything that needs the FORWARD table. If NAT is not working after Docker installation, it is probably because it set the iptables FORWARD policy to DROP.
This may also make you think that your br0 or bridge is not working, but it's likely just due to what we'll mention later on below, that, Docker probably set your FORWARD chain to default DROP all packets, so nothing on your bridge ever makes it out........
If you are doing a custom deployment and image, make sure that when you rsync'd or tar'd that you didn't mess up the symlnk of /etc/mtab to /proc/self/mounts
ln --force -s /proc/self/mounts /etc/mtab
Will fix this........
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........
In this scenario, let's say you want to clone your OS at the filesystem level and the source system (the system you want to clone from) is in use.
Doing a blind rsync / is a big problem because it uses twice as much space for no reason.
The reason for this is that with ecryptfs you have a /home/.ecryptfs directory which has the actual encrypted versions of your files and folders. However your home directory (eg. /home/someuser) is mounted.
Doing the blind rsync will ca........
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........
Just use apt-cache policy to find the repo of a package:
apt-cache policy lxd
lxd:
Installed: 3.0.3-0ubuntu1~18.04.2
Candidate: 3.0.3-0ubuntu1~18.04.2
Version table:
*** 3.0.3-0ubuntu1~18.04.2 500
500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
&nb........
This can be used on almost anything, since Gluster is a userspace tool, based on FUSE. This means that all Gluster appears as to any application is just a directory.
Applications don't need specific support for Gluster, so long as you can tell the application to use a certain directory for storage.
One application can be for redundant and scaled storage, including for within Docker and Kubernetes, LXC, Proxmox, OpenStack, etc or just your image/web/video files or even da........
Let's say you have a VM file that uses 200G of dynamic space, but really only has 40G in usage. If you add fles and delete, at some point the file will be larger than the current space you are using.
Take this image which shows is using 71G of space on the host:
The actual space being used inside the image is about 43G as we can see:........
This may be necessary if you have a VM or if for some reason you just want to be more efficient with your space and have the flexibility of changing your swap space at will.
What we mean is the ability to use a "swap file" or similar to the Windows "pagefile" that normally resides on the root or c: partition of Windows.
Here's all you have to do and then you to can have a single partiton with everything, including the swap file on the root partition if you........
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.........
Why choose OpenVPN instead of a firewall appliance?
OpenVPN can be a reliable and easy replacement for traditional hardware or just be an additional tool that your company uses so that the firewall can focus on its job rather than acting as a VPNappliance at the same time.
When comparing OpenVPN with traditional firewal........
zip is useful to share files across multiple platforms.
A simple way if you want to zip all pdfs:
zip Labs.zip *.pdf
If you want to zip everything in the current directory and subdirectories do this:
zip -r stuff.zip *........
Kubernetes Easy Beginners Tutorial/Architecture Guide
Kubernetes is known as container orchestration and we should start at explaining the container part of it.
A Container is what runs the actual application and based on an Image, and are more comparable to something like an LXC Container, Virtuozzo/OpenVZ using the Linux Kernel Namespaces feature. Containers run these images as independent, isolated operating environments under the O........
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........
This is a common issue when e-mailing or uploading video files.
One note is that you should make the filesize you choose below about 20% smaller than you need. For example I took a 219MB video and told it to be 20M. The resulting file was still about 21.9M but it was OK when I said 18M and was barely below the 20M size.
ffmpeg is our friend here, just use this command:
Change the -fs 100Mto the size you want eg. 20M, 500M
Chan........
Just a quick note and warning is that if you are testing to see if EFIPXE booting works on a VM, MAKE SURE it actually works. For example Iinitially tested using my Distro's QEMU 2.5+dfsg-5ubuntu10.46 and ovmf BIOS firmware (OVMF supports EFI). However, I found on old versions of QEMU (like 2.5), EFIbooting with GRUB NEVER works so it may appear that you have made a mistake when everything is fine when you boot a physi........
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........
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........
$ ./test.sh
bash: ./test.sh: Permission denied
This happens normally because you are on a partition that was mounted as "user" and without the exec option. Also be sure to add exec at the end so no other options set noexec.
Change your fstab or add exec to your mount options:
/dev/md127 /mnt/md127 ext4 auto,nofail,noatime,rw,user,exec 0 0
........
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........
When you automount a drive in /etc/fstab even if it's not important like an external drive that you only use sometimes and is not required for booting, it will prevent a successfuly boot.
If you disable quiet mode for booting you will see something like below "A start job is running for dev-disk ...."
How do we fix an fstab entry from preventi........
It really seems limited in that it can mainly give you the things you would see on the physical unit such as load etc..
wget https://downloads.sourceforge.net/project/apcupsd/apcupsd%20-%20Stable/3.14.14/apcupsd-3.14.14.tar.gz?r=https%3A%2F%2Fsourceforge.net%2Fprojects%2Fapcupsd%2Ffiles%2Flatest%2Fdownload&ts=1598115866
tar -zxvf apcupsd-3.14.14.tar.gz
cd apcupsd-3.14.14
[root@somebox apcupsd-3.14.14]#
./conf........
-?????????? ? ? ? ? ? shadow
----------. 1 root root 748 Jul 10 04:35 shadow-
cat: shadow: Input/output error
If you see this you are probably in big trouble, it could be a physical error or if it's a VM image that it is corrupted due to a physical error on the underlying disk/array/NAS or it could a........
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........
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........
This is caused because the user is running as qemu for virt-resize and if qemu does not have privileges to read from the source and write to the destination, it will fail with the below. So either change the uid of qemu or change the ownership of the source and target.
Solution:
export LIBGUESTFS_BACKEND=direct
virt-resize --expand /dev/sda2 /root/kvmtemplates/windows2019-eval-template.img /root/kvmguests/kvmkvmuser4515........
It is unfortunate that LXC's dir mode is completely insecure and allows way too much information from the host to be seen. I wonder if there will eventually be a way to break into the host filesystem or other container's storage?
OpenVZ better security:
[root@ev ~]# cat /proc/mdstat
cat: /proc/mdstat: No such file or directory
/dev/simfs 843G 740G 61G........
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]
 ........
A big problem over ssh and especially sshfs is that your connection will often timeout and disconnect after inactivity.
To fix this you can modify the server but it may not be practical or you may not have access. Why not send keep alives fom your end (client side)?
Just edit /etc/ssh/ssh_config (not to be confused with sshd_config as that is the server side):
Find the line that says "Host *" and change it like this:........
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 reason for doing this is that the installer doesn't seem to work properly for LUKS and the server installer doesn't even support LUKS anymore. When you use the GUI install on Desktop for LUKS it won't boot and will just hang after you enter your password. So the only reliable way is to do it ourselves.
1.) Make a default minimal install of Ubuntu
2.) Have a secondary disk on the server or VM.
3.)........
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 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)........
If you can print other PDFs but not a particular one it is very likely that the PDF size is A4 (the longer, skinnier Asian paper size) instead of the North American letter size ( 8.5" x 11"). This breaks printing in most cases. Or it may print if you find a program that ignores the size issue.
Here is an example of an A4 being rejected by a printer in Ubuntu Linux via CUPS
Cannot print PDF CUPS Samsung C460:
Processin........
Adjust to suit your needs. Currently this would kill any whois process running for more than 30 seconds or more than 1 minute.
Add it as a cronjob. The motivation is that some commands have no timeout and just end up using up CPU and memory for no reason while never exiting to free resources.
#!/bin/bash
IFS=$(echo -en "nb")
for pid in `ps aux|grep whois`; do
echo "pid=::$pid::&qu........
By default at least on Centos 7 nfs only allows 8 connections and starts 8 nfsd daemons.
To fix this edit this file:/etc/sysconfig/nfs
Edit the line "RPCNFSDCOUNT" (uncomment it so it looks like this:
RPCNFSDCOUNT=30
In the example above we are setting 30 nfsd daemons to run (or in other words 30 connections are possible this way).........
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`........
Install Errors on Version 12:
This error happened on QEMU emulator version 2.11.1 pve-qemu-kvm_2.11.1-5
on Proxmox/Debian but installing on QEMU.12 on Centos 6 did not produce the error.
*Update it is not related to the OS or QEMU version. This happened in Centos 6 too after a second install.
What really causes this even though you successfully install........
The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs.
qemu-kvm command:
/usr/libexec/qemu-kvm -version
QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard
........
For some reason, perhaps you don't want to run a daemon or let Letsencrypt have access to your production server.
There is a way to use it like a normal CSR/CA setup in manual mode.
./letsencrypt-auto certonly --manual -d realtechtalk.com - www.realtechtalk.com
Eventually you will get prompted to create a certain path and file with certain data:
Create a file containing just this data:
Casdfasfadsfsad........
This works on the 2000 and 3000 series generally.
*The easy way is to just hold the mode button for 10+ seconds.
The full/proper way is below:
1.) Either power on the unit and hold the "mode" button or hold the "mode" button until you see the below:
00:04:08: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvram
00:04:08: %EXPRESS_SETUP-6-CONFIG_IS_RESET: The configur........
The key thing is that you must use a "machine"id of "pc-1.3" or it will say your hardware is not supported.
Additionally you MUST use a virtio disk or you will get a ks_pre.sh error as soon as the install starts (a look at logs will show it can't find a disk). This is funny because even though the OS finds the disk and an fdisk -l shows it, it looks like the script looks for a /dev/vda device (virtio) and nothing else, so if you didn't use Virtio as you........
What you need to do if you have taken a dd or real raw image dump of a hard disk:
VBoxManage convertdd windows2019-eval-template.img windows2019.vdi --format VDI
The .img is the raw dd dump and the .vdi is the output file.
--format VDIspecifies to output to .vdi format
If you are in a pinch you can always use qemu-kvm binary and manually specify the .img as your disk and i........
Do you hate how Centos 7 defaults to allocating most of your valuable space to /home even though it is a production server?
Here is a quick guide on how to take back that space live, while online (of course make sure you have backups just in case something goes wrong!):
First we will reduce our home dir by 100G:
lvreduce -L -100G /dev/mapper/centos-home
WARNING: Reducing active and open logical volume to ........
Jan 30 17:16:10 localhost sshd[25385]: error: Failed to allocate internet-domain X11 display socket.
The solution for me on the server side was the following in sshd_config:
AddressFamily inet
*Remember to restart sshd and also reconnect from the client side.
Ihad all the normal X11 settings on the server but it just stopped........
size = the amount of RAM (m for megabytes)
/mnt/ram = the mount location of the ram disk (change to the path you want it mounted to)
mount -t tmpfs -o size=4096m tmpfs /mnt/ram/
Example test in an old server:
You can see that when reading if you don't specify bs1=M the read speeds are several times slower (eg. 450MB/s vs 2.1GB/s)
mount -t tmpfs -o size=4096m tmpfs /mnt/ram/^C
root@testserver:~# dd........
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........
growisofs -Z /dev/sr0 critical.tar.gz.gpg
Executing 'genisoimage critical.tar.gz.gpg | builtin_dd of=/dev/sr0 obs=32k seek=0'
I: -input-charset not specified, using utf-8 (detected in locale settings)
File critical.tar.gz.gpg is larger than 4GiB-1.
-allow-limited-size was not specified. There is no way do represent this file size. Aborting.
:-( write failed: Input/output error
#remember to us........
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........
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........
initiator = client
target = server
These are the first concepts you should understand which is that in iscsi essentially the "initiator" is the client and the "target" is the server.
iSCSI is derived from the old fashioned SCSI that us oldtimers grew to love. The "i" stands for Internet and the SCSI stands for "Small Computers Systems Interface" (SCSI).
iSCSI Target (Server)Setup
targetcli is the pac........
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........
Proxmox at the root of your storage creates and "images"and "templates/iso" folder for VM images and iso's respectively. It ignores files in any other location.........
Error 0 occurred while receiving the document
root@vh1:/var/tmp# wget http://mirror.compevo.com/proxmox/proxmox-ve_5.2-1.iso
--2018-08-30 16:27:37-- http://mirror.compevo.com/proxmox/proxmox-ve_5.2-1.iso
Resolving mirror.compevo.com (mirror.compevo.com)... 103.25.61.44
Connecting to mirror.compevo.com (mirror.compevo.com)|103.25.61.44|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 641517568 (612M) [application/o........
You get errors like below and see you have all question marks for the permissions if you go to /run/user/1000/gvfs
If you try to access the mounted share such as anything mounted as gvfs like an SSH share in your file manager you may get an error like this. It generally means an interruption in communication or a fault with gvfsd has caused it.
Solutio........
[root@localhost:~]
BootModuleConfig.sh echo host-ind nfcd........
yes it does create its own json
============================================
cat /tmp/vcsaUiInstaller/ovftool-20180809-175238948-20180809-175603497.log |grep -i json
2018-08-09T17:56:04.238-07:00 verbose OVFTool[30966] [Originator@6876 sub=Default] Manifest file entry: SHA1(VMware-vCenter-Server-Appliance-6.7.0.12000-8832884_OVF10-file1.json) = 1deb658c724767697587d5909c4051c01813e6a1
--> ........
Server Side Config
1.) First install nfs-utils
yum -y install nfs-utils
2.) Configure nfs share
Create a directory for your NFS share
mkdir /datastore
Create your NFS share in /etc/exports
echo "/datastore 10.220.101.0/24(rw,sync,no_root_squash)" >> /etc/exports
systemctl restart nfs........
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........
nfs mount failed:
mount 10.10.2.20:/tmp/nfsmount /mnt/nfs/
mount: wrong fs type, bad option, bad superblock on 10.10.2.20:/tmp/nfsmount,
missing codepage or helper program, or other error
(for several filesystems (e.g. nfs, cifs) you might
need a /sbin/mount. helper program)
 ........
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,........
Sometimes if you have a very basic configuration OpenVPN on the client side for some reason sends all traffic to the OpenVPN server IP through the tun0 which is of course impossible and creates a block or routing loop.
This is because you need to use your normal ISP/LANgateway to hit the OpenVPN server if it is remote/offsite as is usually the case. So if you are connected to the OpenVPN through say a tun0 device and your routing is set to connect to the OpenVPN&nbs........
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 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........
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........
The easiest way is to use SSHand DD or a combination of netcat. SSHwill be a little slower due to encryption but is the most secure way (on two older systems the average clone speed is about 40-50MB/s). This is also OS independent as it doesn't matter what the source OS is because you are literallly cloning the drive so you retain the partition table and settings.
Clone HDD using SSH and DD........
I don't recall having this issue in the distant past but nowadays at least Debian seems to be very picky about this.
I used dd to copy one hard drive to another and tried booting it. Everything seemed fine with grub working but each time it would drop to the busybox shell. There is no particular error so this is misleading.
Normally the first things you would check are to make sure your fstab is correct (that the UUID is correct)and that you've updated grub.&........
pcimodules no longer works it produces nothing probably because the format of /sys/bus/pci is different.
lspci -k doesn't work on older lspci versions.
pciutils can be compiled but it won't work if you have an old system and compile on a newer glibc.
iteriate through /sys/bus/pci/devices/*/modalias
cat /sys/bus/pci/devices/*/modalias
pci:v00008086d00001237sv00000000sd00000000bc06sc00i00
pci:v00008086d00007000sv0000000........
guestmount -a kvmuserscra.img -m /dev/sda1 mount
libguestfs: error: mount_options: /dev/sda1 on / (options: ''): mount: unknown filesystem type 'ntfs'
guestmount: '/dev/sda1' could not be mounted.
guestmount: Did you mean to mount one of these filesystems?
guestmount: /dev/sda1 (ntfs)
guestmount: /dev/sda2 (ntfs)
yum -y install ntfs-3g
still........
virt-list-partitions kvmusertest.img
/usr/bin/supermin-helper exited with error status 1.
To see full error messages you may need to enable debugging.
See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs at /usr/bin/virt-list-partitions line 177.
#solution
update-guestfs-appliance........
sudo mount -a
Unable to find suitable address.
[35758.706993] CIFS VFS: Error connecting to socket. Aborting operation.
[35758.707247] CIFS VFS: cifs_mount failed w/return code = -111
[35795.476160] CIFS VFS: Error connecting to socket. Aborting operation.
[35795.476346] CIFS VFS: cifs_mount failed w/return code = -111
When the above happens "Unable eto find suitable address" it usually means the smb nam........
To get the first X letters of a word:
It's very simple you can just pipe it to head with
-c 1 (gives the first letter and so on)
-c2 (2 gives the first 2 letters).
echo "dsjfsdlksjdklf;jlsd;kflasdj;kl"|head -c 2
Returns ds
To get the last X letters of a word:
Now we use tail with -c but it works differently. ........
The easiest way to recover or mount an off-line ecryptfs directory is the built-in command from ecryptfs
sudo ecryptfs-recover-private It will find your wrapped passphrase and ask for your password and mount it in tmp. Much easier especially when your current active OS is using ecryptfs too.
This a fantastic tool when going through old backups.........
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........
When using the .sh script the rendering doesn't work after an upgrade of related packages to kdenlive.
kdenlive (kdenlive:amd64 (4:17.04.1+git201705191233~ubuntu16.04.1)) with affine or composite transitions was fine but is now broken during the time of transition it is just a white screen.
The previous version was fine:
kdenlive:amd64 (4:17.04.1+git201705191233~ubuntu16.04.1
But now I can't find it or install it:........
[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........
#if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used
wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2
tar -jxvf ffmpeg-3.3.2.tar.bz2
cd ffmpeg-3.3.2/
./configure --disable-yasm
install prefix /usr/local
source path ........
Very simple browse to your /boot directory
It does make more sense to extract the image in its own directory eg "initramfs-blabla-dir" as it will literally extract directly to the pwd.
cp initramfs.img someotherdir
cd someotherdir
zcat initramfs-3.10.0-514.el7.x86_64.img | cpio -idmv........
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........
user@box:~$ sudo tune2fs -l /dev/md99
[sudo] password for user:
tune2fs 1.42.9 (4-Feb-2014)
Filesystem volume name:
Last mounted on: /mnt/md50
Filesystem UUID: 976a8655-2619-4587-878c-dab07f7b7652
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Fi........
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........
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........
Here is a simple MP3 player and now there's a reason to understand why the supplied cable has some kind of capacitor and is very short. These devices can be VERY finicky and any voltage fluctuation or difference is enough to cause issues.
Take for example the error messages from Linux Mint:
[804829.895414] usb 1-1: USB disconnect, device number 11
[806961.109030] usb 1-1: new high-speed USB device number 12 using xhci_hcd........
I get the following error "Installer Crashed" on 18.1 MATE 64-bit when installing by NFS/PXE. Yet it was able to at least detect and use my NIC (perhaps the driver was only activated because of PXE/NFS being used)?
When using 18.1 Cinnamon on CD the NIC does not work but the installer did succeed. However it doesn't work right, I can't login graphically and get some Cinnamon OOMerror but how can this be with 8GB of RAM straight from login?........
*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"........
espeak - is horrible and sounds very old and robotic
echo "hello there"|espeak
#don't know how to use
mbrola and plugins
cicero
jovie just seems to be a graphical interface to espeak
There is also sbreader/sapi
Google's Text To Speech Works Quite Well
#!/bin/bash
say() { local IFS=+;/usr/bin/mplayer -ao alsa -really-quiet -noconsolec........
ecryptfs-mount-private
Enter your login passphrase:
Inserted auth tok with sig [ee16d84] "into the user session keyring
mount: No such file or directory"
[ 156.118113] ecryptfs_mount: kern_path() failed
[ 156.118431] Reading sb failed; rc = [-2]
[ 164.233055] traps: mate-notificati[3472] trap int3 ip:7f43d7002c13 sp:7fff162c6600 error:0
[ 166.017061] ecryptfs_mount: kern_path() failed........
1.) Replicate the number of partitions in your new drives.
gdisk /dev/sda
gdisk /dev/sdb
I created 3 partitions of the same same size.
partition #1: +1G (/boot)
partition #2: +60G (swap)
partition #3: rest of it (/)
#note if you are using GPT/gdisk you need to create separate a partition at least 1MB in size (in my case I would a 4th partition and mark it type ef02).........
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........
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........
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........
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:........
migrating from an old OpenVZ (Centos 5) to new OpenVZ (Centos 6)
Also if migrating from 32-bit HN to 64-bit your RAM will probably be much bigger than it should be!
16x bigger
eg. 32bit HN:
total used free shared buffers cached
Mem:&nb........
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........
pip install obfsproxy
/usr/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
InsecurePlatformWarning
You are using pip version 7.1.0, however version 8.1.1 i........
Iwill start by saying I think I know what caused this boot-time error on Linux Mint but should also apply to Debian and Ubuntu.
I changed my BIOS time to several hours in the past to match the current time, but this caused Linux to think there were incorrect filesystem times.
The problem is that it seems when you hit this I am not sure what is happening, it doesn't seem to be doing fsck and hangs without prompting the user.
What I have found is that........
Add the following to fstab where 192.168.1.125/Media is the samba share and where /home/homeuser/Downloads is where you want to mount.
Change user and pass to what is needed (if no pass is required it still works fine with the below).
//192.168.1.125/Media /home/homeuser/Downloads cifs user=guest,pass=bla 0 0
mount: wrong fs type, bad option, bad superblock on //192.168.1.125/Media,
&nbs........
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/........
Say you have a bunch of files like this:
file-01.jpg
file-02.jpg
...............
What if you want to mass rename them?
the rename tool can work just like sed
For Debian based distros:
Note "file" is what we search for and "newname" is what we replace it with, so substitute according to your requirements.
rename s/file/newname/ name-file-*.jpg
For R........
In this case we want to mount partition #2
fdisk -lu Centos-6.6-x86_64.img
You must set cylinders.
You can do this from the extra functions menu.
Disk Centos-6.6-x86_64.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders, total 0 sectors
Units = sectors of 1 * 512 = 512 bytes
Device Boot&nbs........
How to Increase The Disk and Partition Size in Windows 2022,2019,11,10,8,7 etc.. Server
1, Enter the command prompt
Start -> cmd
2. Start diskpart
diskpart
3. Find the drive that has the wrong size
list volume
4. Select the volume (in this example we use volume 2)
select volume 2
5. Extend the volume........
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 ........
mount -o bind /somedir /anotherdir
In /etc/fstab
/somedir /anotherdir none bind 0 0........
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........
I never did get it working, it is too bad as obfsproxy should really be an option and integrated into the OpenVPN client and server or something similar:
yum -y install python-pip python-devel
No package python-pip available.
#install the EPEL repo
python-pip install obfsproxy
python-pip install obfsproxy
-bash: python-pip: command not found
pip install obfsproxy
&........
root (hd2,1)
Filesystem type unknown, partition type 0x83
grub> root (hd2,2)
root (hd2,2)
Filesystem type is ext2fs, partition type 0x83
grub> setup (hd2)
setup (hd2)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... no
#weird thing about grub is that the drive you enter is considered hd0
For example when booted fu........
Fortunately the format is EATX so an EATX case will work and the screw layout is standard.
You will need to remove the HEX/TORX screws that are connecting the stock HP standoffs (meant to slide into an HP case).
XW9400 Motherboard Issues
Size: 12" x 13"
Proprietary Power Connector
Proprietary CPU Power Connector
Proprietary Memory Power Connector
Fan connectors are 4 pin so you will need some kind of adapter.........
Motherboard: Gigabyte GA-3CESL: http://b2b.gigabyte.com/products/product-page.aspx?pid=2658#dl
Dell Part Numbers for the motherboard: R1232 R1232L R2232S SERVER MOTHERBOARD GENUINE 408P9 CN-0408P9
GA-3CESL Manual Download here
RAMSlots: 16 (8 controlled by each CPU)
RAMType: DDR2 ECC 5300P........
It looks like newer versions of Centos no longer have encfs so you have to compile it, only it does not work and fails so those wanting encfs should probably use any other OS which supports it better.........
Dell CS24SC Info
0000:00:00.0 Host bridge: Intel Corporation 5100 Chipset Memory Controller Hub (rev 90)
0000:00:02.0 PCI bridge: Intel Corporation 5100 Chipset PCI Express x8 Port 2-3 (rev 90)
0000:00:03.0 PCI bridge: Intel Corporation 5100 Chipset PCI Express x4 Port 3 (rev 90)
0000:00:04.0 PCI bridge: Intel Corporation 5100 Chipset PCI Express x16 Port 4-7 (rev 90)
0000:00:05.0 PCI bridge: Intel Corporation 5100 Chipset PCI Express x4 Port 5 (rev 90)........
0000:00:00.0 Host bridge: Intel Corporation 5000P Chipset Memory Controller Hub (rev b1)
0000:00:02.0 PCI bridge: Intel Corporation 5000 Series Chipset PCI Express x8 Port 2-3 (rev b1)
0000:00:03.0 PCI bridge: Intel Corporation 5000 Series Chipset PCI Express x4 Port 3 (rev b1)
0000:00:04.0 PCI bridge: Intel Corporation 5000 Series Chipset PCI Express x8 Port 4-5 (rev b1)
0000:00:05.0 PCI bridge: Intel Corporation 5000 Series Chipset PCI Express x4........
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........
If the below is happening on KVM (a very weird and scary looking error) it's probably because of Windows. This has happened countless times to me where the bootsector on Windows 7/2008 becomes corrupted easily (even by a crash or shutdown).
KVM: unknown exit, hardware reason 0x80000021
kvm_run returned -22
rax 0000000000000010 rbx 0000000000000080 rcx 0000000000000000 rdx 0000000000000080
rsi 000000000025db2a rdi 000000000007db2a rsp 0000000000000200 rbp........
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........
libguestfs tools howto guide for managing virtual machine images.
libguestfs-tools aka guestfs tools has a lot of tools that make this very easy for you. You can easily mount partitons from an image with some of the commands below.
To mount a partition
#mount the kvmuser102821.img image and the /dev/sda1 partition from it to the local directory "mount"
guestmount -a kvmuser102821.img -m /dev/sda1 mount
........
It's simple, just edit /etc/vz/vz.conf and add or change the following:
VE_LAYOUT=simfs........
This error seems to happen randomly and especially when trying to send e-mails. Apparently it's a long-standing GNome bug but is also partially the default of Thunderbird depending on who you ask. There is no known fix that I'm aware of except to upgrade gnome and the gvfs package but this is not an option for older versions/distributions.
An error occurred while loading or saving configuration information for thunderbird. Some of your configuration settings may not........
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........
#count=10000 makes an image of 10000MB make sure your image is at least the same as your existing
dd if=/dev/zero of=yourimage.img bs=1M count=10000
# losetup -fv newimage.raw
# fdisk -cu /dev/loop0
# kpartx -a /dev/loop0
# dd if= of=/dev/mapper/loop0p1
# e2fsck -f /dev/mapper/loop0p1
# resize2fs /dev/mapper/loop0p1
# a lot of guides tell you to edit /etc/fst........
fdisk unfortunately can't do this and I'm not sure if there's any updated version that handles it but parted can do it.
Here's an example of how to do it:
parted /dev/sda print
1 17.4kB 1024MB 1024MB ntfs primary
2 1024MB 16144MB 15120MB ntfs primary
/dev/sda1 would be the first partiton
/dev/sda2 would be the second partition
You can then just access them like any other normal partition.........
./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........
Error: Package: php-Monolog-dynamo-1.7.0-1.el6.noarch (epel)
Requires: php-aws-sdk
Error: php-pecl-zendopcache conflicts with 1:php-eaccelerator-0.9.6.1-1.el6.x86_64
Error: php-xcache conflicts with php-pecl-apc-3.1.9-2.el6.x86_64
Error: php-pecl-zendopcache conflicts with php-pecl-apc-3.1.9-2.el6.x86_64
Error: Package: php-horde-Horde-Vfs-2.1.2-2.el6.noarch (epel)
&n........
I never found a solution to do it live (nothing worked that I found) so it looks like a relogin is required.
Check your maximum file limit
cat /proc/sys/fs/file-max
824460
This is different than your actual's user limit which you'll see below
ulimit -n
1024
Try and set it higher but it won't work
ulimit -n 65000........
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........
mount -o bind /proc /sda2/proc
mount -o bind /dev/ /sda2/dev
mount -o bind /sys /sda2/sys
chroot /sda2
mint / # mount -o bind /proc /sda2/proc
mint / # mount -o bind /dev/ /sda2/dev
mint / # mount -o bind /sys /sda2/sys
mint / # chroot /sda2
mint / # cd ~
mint ~ # ls
Desktop
mint ~ # cd /
mint / # ls
bin Desktop dev-temp home&nb........
The first is a dual CPU AMD Opteron 2373EE (4 cores x 2) and I think it did bad because it has some old 250GB SATAs which can only do about 65MB/s max sequential reads. I think it should have blown away the second (AMD X4 640 Quad Core).
[root@fs12home unixbench-4.1.0-wht-2]# ./Run
make all
make[1]: Entering directory `/root/unixbench-4.1.0-wht-2'
Checking distribution of files
./pgms exists
./src exists........
I've got one of these for testing projects from work at home and got more than I bargained for with the time I've spent on it due to the storage handing/Perc 6/i cards.
My particular model came with the following:
2U Rack Mount Server with Rails
2xOpteron 2373 EE (Quad Core, there is a 6-core version that can be found at times)
16GB RAM
2 x 250GB Seagate SATA
2 x Dell Perc 6/i (horrible and a nightmare to work........
The results are not bad, the Hitachi performs the same as it does in a SATA2 motherboard. However, the 2TB is much different, on a similar 2TB Toshiba I get about 198MB/s on a different motherboard vs the 2TB Hitachi which should produce similar results.
This Dell Perc 6/i is on a PCI x8 riser card and is connected to a 12-port backplane.
Adapter #0
Enclosure Device ID: 32
Slot Number: 0
Enclosure position: N/A
De........
One thing to remember is that you need MegaCli to do the flashing.
You also need the correct file,I tried at least 2 different Perc 6 firmwares from Dell that kept getting rejected as corrupt by MegaCli(they were really the wrong version). I have an external PCI-E Dell 6 Perc/I butI chose images from the 'Integrated" on motherboard version as it was allI could find. They are different, and below is my first time finding success.........
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........
LSi Megaraid
At first it was configured as a RAID 0, then I deleted the Virtual Disk Group.
I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing.
To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
pxe-32 tftp open timeout
The solution was to enable tftp in xinetd with "chkconfig tftp on".
See the troubleshooting below:
chkconfig --list
NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off
acpid 0:off&n........
This happens all the time, you are reading from a textfile which has spaces eg:
datainfo 00
datainfo 11
If you do loop on it like this:
for info in `cat $file`; do
echo "info=$info"
done
It will treat datainfo and 00 as two separate lines:
info=datainfo
info=00
Obviously that's not what we want and there are many weird solutions in bash bu........
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.........
mkdir: cannot create directory 'test': Disk quota exceeded
You are out of inodes usually:
df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/simfs 200000 200000 0 100% /
none ........
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........
I'm using ecryptfs and was suddenly unable to access or even ls my home directory (but every subfolder is accessible). It just hangs and throws this message in messages/dmesg:
Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO
I read somewhere that perhaps some file or folder is owned by root somehow, sure enough there are some and sudoing to root allows me to........
After some fsck issues I can't boot my Centos 6.4, this just keeps repeating over and over.
init: tty (/dev/tty2) main process (1031) terminated with status 1
init: tty (/dev/tty2) main process ended, respawning
Disabling SELinux through Single User mode fixed this.........
Solution To The Following:
yum -y install zlib-devel
yum -y install e2fsprogs*
*** Cannot find /usr/include/et/com_err.h. (yum install libcom_err-devel) ***
Installation didn't pass, halting install.
Once requirements are met, run the following to continue the install:
cd /usr/local/directadmin/scripts
./install.sh
Common pre-install commands:
http://help.directadmin.com/it........
cat | grub --device-map=/dev/null
Now pay close to the attention of the beginning.
Type: "device (hd0) VPS.img" this is telling what hd0 will be to GRUB and we're telling it the disk image file "VPS.img" in the current directory is hd0, you can specify alternate paths and image names of course.
GNU GRUB version 0.97 (640K lower / 3072K upper memory)
[ Minimal BASH-li........
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........
df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_12-lv_root
50G 1.2G 46G 3% /
tmpfs 7.8G 0&nb........
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........
The best way is to use rsync, I've set it up so it doesn't copy unnecessary files, or at least ones I'm sure aren't needed.
Here is the rsync command Iused (adapt to your specific Thunderbird profile location):
rsync -hazv user@remotehost.com:/home/user/.thunderbird/sbrer.default/* /home/user/.thunderbird/4nyb0.default/ --exclude=global* --exclude=Cache --exclude=ImapMail --exclude=Mail
This is a great way to get your e-mail accounts going on a new c........
I backed up everything in the /mnt/sd_card directory thinking that some dataloss could occur for some reason but purposely left my microSDHC unbacked up thinking that "it won't touch that since it's external" and Samsung's and other manufacturers website even say this (that it won't be affected and not to worry etc).
Apparently I was wrong, my microSD was "undetected" and asked to be formatted after the upgrade (there goes 3-months worth of family photos). No........
The best way I could figure out is to use another guest of some sort to do this, while assigning the disk that needs to be resized to the same guest.
So say we have /dev/xvda as the guests drive and we've booted it up.
We also have /dev/xvdb (this is going to be the image/disk to be resized).
In this case it's based on an ext3/4 image.
Run e2fsck on it to ensure there are no filesystem errors.
e2fsck /dev/xvdb........
Disk /dev/sda: 320.0 GB, 320072933376 bytes
256 heads, 63 sectors/track, 38761 cylinders
Units = cylinders of 16128 * 512 = 8257536 bytes
Device Boot Start End Blocks Id System
/dev/sda1 1 38........
ERROR 1045 (28000): Access denied for user 'contentmanager'@'localhost' (using password: YES)
For fun I thought I'd reset the password:
GRANT ALL ON thecontent.* TO contentmanager IDENTIFIED by 'dfdfsdfdsfsdfsd';
ERROR 1470 (HY000): String 'contentmanager' is too long for user name (should be no longer than 16)
This is ridiculous that this new version has some bizarre 16 character username limit and not only that but i........
This is just how I like things, quick and simple through CLI (command line) using gifsicle for free.
gifsicle --colors 256 --delay=200 --loop banner.gif banner-page2.gif > banner.gif
banner.gif = the first page of the banner
banner-page2.gif = the second page
--delay=200 ms to switch between the two
--loop=it goes back and forth between the two pages forever
banner.gif=the resulting animated gif.
There are many other opti........
After about 15 tabs I believe, they become hidden on the right side and are accessible only by furiously clicking the "right arrow" and even then it takes forever and honestly this hidden tab feature seems to slow down everything.
If you enter "about:config" in your browser without the quotes just set this value to get rid of this annoying (one of many new) feature from Firefox (set it to false and restart your browser):
services.sync.prefs.sync.brows........
fdisk -lu VPS.img
last_lba(): I don't know how to handle files with mode 81ed
You must set cylinders.
You can do this from the extra functions menu.
Disk VPS.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders, total 0 sectors
Units = sectors of 1 * 512 = 512 bytes
Device Boot Start End ........
One of my test Centos 5 containers was on a partition that filled up and it threw all sorts of errors and stopped responding but now I can't boot it again anymore.
All the console shows is the Linux Penguin on the top left corner and the xm console says "usbcore: registered new driver hub" and has halted there.
Centos 5 Xen container stuck/frozen won't boot on "usbcore: registered new driver hub"
Another great way of troubleshooting is booting fro........
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........
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........
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........
GNU GRUB version 0.97 (640K lower / 3072K upper memory)
[ Minimal BASH-like line editing is supported. For the first word, TAB
lists possible command completions. Anywhere else TAB lists the possible
completions of a device/filename.]
grub> root (hd1,0)
Filesystem type is ext2fs, partition type 0xfd
grub> setup........
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........
I don't expect this to be solved soon but some of Yahoo's DNS servers are out of whack. I changed the IPs of some nameservers of some domains and now most Yahoo users can't e-mail to those domains!
As you can see below by the "No MX or A records for mychangedomain.com", now Yahoo's DNS/mailserver DNS cache is wrong. You would think they would at least have cached the old incorrect records, but instead for some reason their DNS cache has no entry and doesn't seem........
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........
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........
Centos 5 Postfix and SPAMASSASSIN Tutorial
yum install spamassassin
chkconfig spamassassin on
vi /etc/mail/spamassassin/local.cf
##############
#required_hits 5
#report_safe 0
#rewrite_header Subject [SPAM]
#5 is the least restrictive (means only the most obvious SPAM is caught. 0 is obviously the most restrictive/sensitive and would have lots of false positives
require........
umount: /home/diret/mount: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
I tried everything (fusermount -u) to unmount it but the only thing that worked was actually doing this:
ps aux|grep sshfs
Then I identified the sshfs connection and did:
kill -kill pid........
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........
Openvz problem, it is confusing because it's an inode issue and there is enough free space.
cp: cannot create regular file `forums/memberlist.php': Disk quota exceeded
/dev/simfs 60G 20G 41G 33% /
none 2.0G 4.0K 2.0G 1% /dev........
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........
Webmin Setup Centos 5:
wget http://downloads.sourceforge.net/project/webadmin/webmin/1.530/webmin-1.530-1.noarch.rpm?r=http%3A%2F%2Fwww.webmin.com%2Fstandard.html&ts=1294339690&use_mirror=surfnet
[1] 24229
[2] 24230
[root@host ~]# --2011-01-06 21:48:20-- http://downloads.sourceforge.net/project/webadmin/webmin/1.530/webmin-1.530-1.noarch.rpm?r=http%3A%2F%2Fwww.webmin.com%2Fstandard.html
Resolving downloads.sourceforge.net... 216.34.181.........
It seems nearly anything can make rhythmbox crash, I've always found it buggy.
This crash seems to be something related to ecryptfs but it's hard to say. After re-opening rhythmbox so it sits in the Gnome panel/tray, and letting it load/find all of my songs let's it work again. If I show it too soon (I wait 10-15 minutes for everything to scan first) then it will crash over and over.
[171938.995645] ecryptfs_read_and_validate_header_region: Error........
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........
I separated the 2 drives in the RAID 1 array.
1 is the old one /dev/sda and is out of date, while the separated other one /dev/sdc was in another drive and mounted and used with more data (updated).
I wonder how mdadm will handle this:
usb-storage: device scan complete
md: md127 stopped.
md: bind
md: md127: raid array is not clean -- starting background reconstruction
raid1: raid set md127 active with 1 out of 2 m........
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........
Moving to RAID was a pain.
What you have to do is the following from an existing install:
Install mdadm
Create your mdadm RAID 1 array on your spare hard drive.
Start it with the missing disk.
rsync the entire contents of your current / to the md partition.
Here's a good way of doing it:
rsync -Pha --exclude=/proc/* --exclude=/sys/* --exclude=/mnt/* /. /mnt/md2........
From a LiveCD or if you're doing something like converting your non-RAID install to mdadm here's how you would chroot properly (you have to mount your proc, sys and dev on the running system/LiveCD to your chroot environment if you want things to work right, especially if you need to run update-initramfs due to a driver change etc..)
*replace "path" with your mount/chroot path
mount -o bind /proc /mnt/path/proc
mount -o bind /dev/ mnt/pa........
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........
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........
This is based on Debian Linux but should apply equally to any *nix distro.
Install LUKS/crypt-setup
apt-get install cryptsetup
Setup your LUKS Partition
Of course change /dev/md2 with whatever partition you intend to use LUKS on.
cryptsetup --verbose --verify-passphrase luksFormat /dev/md2
You'll be asked to verify your decryption password twice
*DO NOT FORGET THIS PASSWORD AS IT IS NOT RECOVERABLE!........
I've never understood how to enable and disable services for different run levels in Debian based distros, it's just weird, annoying and doesn't make sense. I much prefer chkconfig from RHEL.
Just install the package called 'rcconf' and be done with it. rcconf makes things easy for you.
apt-get install rcconf
Reading package lists... Done
Building dependency tree
Reading state information... Done........
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........
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........
It's not just as simple as running the chroot command, you need to ensure the /proc and /dev entries are passed through and populated to the chroot environment.
Step 1 - Mount Your Off-lineOS
mount /dev/sda1 /mnt
Step 2 - Mount Proc
mount -t proc none /mnt/proc
Step 3 - Mount Dev
Most guides will tell you to use this: mount -o bind /dev /mnt//dev but that doesn't work for some reason in many cases:
mount: wron........
Out of memory: kill process 7559 (rsync) score 635 or a child
Killed process 7559 (rsync)
I was surprised to see this in my dmesg whenmy rsync backup suddenly stalled/stopped.
This system has 3 gigs of RAM and lots of free memory so I don't understand what is happening.
rsync invoked oom-killer: gfp_mask=0x200d2, order=0, oomkilladj=0
Pid: 7600, comm: rsync Not tainted 2.6.24.2 #83
[] oom_kill_pr........
Seagate Inventory/Firmware Check
I heard about this issue a long time ago but never looked into it. I figured I wasn't affected since my 500GB drives were running for so long. I've been using Seagate's since 2002 and to this day all of the drives I have are alive from Seagate.
*Update the bad news is that I realize one of my 500GB's is about to die, it's not even a year old, but is also not affected by the recall according to Seagate!
Seagate Inventory/Firm........
Before we start I take no responsibility for this, you should have a backup and if you make a mistake during this process you could wipe out all of your data. So backup somewhere else before starting this as a precaution, or make sure it's data you could afford to lose.
The RAID 1 Setup (Hardware Wise)
I've already setup my 2 x 1TB (Seagate) drives with identical partitions, make sure your new hard drive (the empty one) is setup like your curr........
I have no idea why but mkfs.ext3 defaults to a patheticlly small blocksize of 1024 bytes/1KB (kilobyte). That means the maximum filesize is ONLY 16GB! With 2KB/2048 bytes you get a 256 GB maximum filesize, and with 4KB/4096 bytes you get 2TB!
I finally noticed/paid attention to this after realizing that with rsync and scp that no file larger than 17GB could be transferred. I then realized it must be a file size limit on the partition.
Here is what tune2fs tol........
I decided on using yum to help me decide even though I normaly use proftpd I decided to see what else I could find.
yum search ftp
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* rpmforge: ftp-stud.fht-esslingen.de
* base: mirrors.netdna.com
* updates: updates.interworx.info
* addons: yum.singlehop.com
* extras: mirrors.netdna.com
rpmforge........
./ntfs-3g /dev/sda1 /mnt -o force
Unexpected sectors per cluster value (127).
Failed to mount '/dev/sda1': Invalid argument
The device '/dev/sda1' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?
This is happening on a system I've come across an HP 6930P running Windows XP Professional. The partition appears to be very norm........
Here are the results, it is Sempron 3000+ AMD Mobile, 500Gig HDD, 512MB RAM with shared ATI Radeon graphics.
# # # # # # # ##### ###### # # #### # #
# # ## # # # #&nb........
PHP cannot access /usr/bin/opensslI have verified the username that runs the process is able to access /usr/bin/openssl and it does exist but the PHP script is saying it doesn't exist:
[code:1:1fd0f3abbe]
if (!file_exists($OPENSSL)) {
//echo "ERROR: OPENSSL $OPENSSL not foundn";
}[/code:1:1fd0f3abbe]
I don't get itI can clearly see the contents of /usr/bin by using the PHP system fu........
Mount Linux ext2 file systemNormally in Linux you could mount ext2 or ext3 etc... like this:
mount -t ext2 /dev/hda1 /mnt/hda1/
In FreeBSD the difference is of course the disk naming conventions (hda1 would be known a /dev/ad0s1):
To mount ext2 in FreeBSD just type:
mount -t ext2[b:68c16c60bf]fs[/b:68c16c60bf] /dev/ad0s1 /mnt/ad0s1........
Mounting NTFS in UnixJust a quick tutorial to mount your NTFS volumes in Unix (FreeBSD/Linux)
[quote:4a9de7bf80]mount -t ntfs -o umask=0 /dev/your_partition /mnt/your_mount_point[/quote:4a9de7bf80]
[b:4a9de7bf80]-o umask=0[/b:4a9de7bf80] is to ensure all users can access the mounted partition (otherwise don't use it and only root can access the mounted partition)
[b:4a9de7bf80]-t ntfs[/b:4a9de7bf80] is simple because it just lets mount kno........
Basic Port ListingHopefully someone finds this useful or at least interesting.
http://www.sans.org/top20/#u9
Name Port Protocol Description
Small services ........
*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........
You can see the problem below, GRUB recognizes my hard drive and sees the partitions but cannot access them. This is from the GRUB boot disc I'm using.
What happened is that I had some power issues causing this system's power to be interrupted several times and basically an on/off on/off situation.
The system won't boot, I just get a flashing cursor and no message or error from GRUB. Obviously the problem is that my MBR seems corrupt or some other issue.
My........
The results are still not flattering and are nothing close to native performance. Unless GlusterFS has a "DRBD-like" option to delay writes over the network and to only read from the client side, I don't see how performance can ever improve much more.
After doing some client optimizations Iadded more to the score:
Start Benchmark Run: Sun Nov 29 00:37:44 PST 2009
00:37:44 up 3 min, 1 user, load average: 0.01........
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........
You might remember my original GluserFS/OpenVZ benchmark which produced a horrible 29.8
This is the exact same system, but using the latest 2.0.8 (with some small files patch which speeds up performance) you can see it is about 25% faster.
I also haven't tuned my config files at all, but there are some settings that should increase performance on small files which I believe i........
This is very disappointing since GlusterFS markets itself as a solution to deploy VPS servers on. On the HNitself I get a Unixbench of about 360.
I'm also using an SSH tunnel to secure the communications, but even before that, things seemed very slow.
# # # # # # # #####&n........
Iwas getting really annoyed with this, I used full quotes around the filename and vi, cat, less all thought I was trying to pass the dash in the filename as an argument.
I didn't realize that all you have to do is just put a dash dash "--"in front.
Here's an example:cat -- "-etc-glusterfs-glusterfsd.vol.log"
Without the -- you get: cat: invalid option -- c
Try `cat --help' for more information.
Ih........
The dmg format is silly and annoying to work with, why couldn't Apple stick with the .iso standard? Anyway, there's an excellent Linux and Windows based tool to convert it back to a normal .iso Image called dmg2iso
I'll only cover theLinux version although the Windows pre-built binary works the same way.
Download dmg2iso here for free (from the author's website)
It's just silly and doesn't make sense that Ubuntu doe........
genisoimage: Directories too deep for 'Backup/My Documents/My Music/iTunes/Album Artwork/Local/5928CE9C1AFAC465/07/15' (7) max is 6.
Some people said choosing the --iso-level-4 option will help. I just opted to add the "-D" switch and everything was fine.........
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........
This will give you the basic info needed to browse and connect to Samba shares from the command line. From the GUI of Gnome or KDE etc, it is pretty standard and straight forward. However, I've found very little guides on how to do it from the command line and if you're like me, a nerd who prefers command line for its simplicity and for remote use, this is the way to go.
First get a list of all the Samba/SMB shares on the target.
smbclient -L hostname........
There's a lot of outdated information and confusion for system administrator's out there.
One annoying task for many an Administrator has been backing up data in Linux. You don't need any GUI tools such as K3B or GnomeBaker. Both are excellent tools but for veteran command line users working remotely, using the keyboard is a great and possibly automated way to save yourself pain and hassle.
At a later date we'll cover how scripting can automatically backup certain........