As a fun test in an old/unloved dual CPU Xeon system, I removed the fan for the heatsink and after 1.5 hours, the system was completely stable and had surprisingly not crashed, despite exceeding or hitting the critical thermal levels........
This example is using RTL8821AU chipset from a TP-Link T2U Plus USB adapter and other similar ones should work the same.
Here's how to get this chipset RTL8821AU working in Linux.
Here's how to get RTL8812 and RTL8822 working in Linux.........
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........
Assign way more replicas than you have of memory on all nodes and watch the Swarm crash which can easily reproduce in a small VMfor testing.
root@Deb11Docker01:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAM........
The error below can be caused by a gateway that is unpingable:
docker swarm join --token SWMTKN-1-1kogg8da68gtb1j7ezaddowyy9s0an5s9tue758o20k18liskw-5h3f61hrrmv3u6agshvbtcklf 172.16.1.80:2377
Error response from daemon: manager stopped: can't initialize raft node: rpc error: code = Unknown desc = could not connect to prospective new cluster member using its advertised address: rpc error: code = DeadlineExceeded desc = context deadline exceeded........
This is a weird issue as sometimes when upgrading or even migrating, this could happen and the reason is simple but maybe not 100% obvious at first.
You will find that your GUIdoesn't load and most services fail to start, even logind
Here are some errors you may see:
Mar 13 22:22:23 rttbox systemd-logind[2892]: Failed to connect to system bus: No such file or directory
Mar 13 22:22:23 rttbox systemd-logind........
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://........
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........
We could always disable swap but this would normally be a bad idea unless you have an incredible amount of RAM and a workload that will never exceed it. However, for live/containerized and high performance environments it could be desirable.
Another middle ground may be to set swappiness to a lower number.
You may also want to clear your kernel's cache, which could be eating up RAM unnecessarily by c........
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........
If you are converting a generic wifi IP camera to ethernet, it may not be that simple as many are default hard coded to a static IP of 192.168.1.168 and login info admin/admin.
From there you can login to the camera and assign it to DHCP by going to http://192.168.1.168
For security these cameras +DVR should be on a separate untagged VLAN or if possible a physically isolated non-internet connected switch/network.
The reference below is applicable to many of the r........
pip3 install requests
Traceback (most recent call last):
File "/home/user/.local/bin/pip3", line 7, in
from pip._internal.cli.main import main
ModuleNotFoundError: No module named 'pip._internal'
As a quick and temp fix call the OS installed python and not the user .local/bin installed pip3
/usr/bin/pip3 install requests
Collecting requests
Cache e........
If you get this error when trying to SSHto a device or machine and you never even got a password prompt:
Too many authentication failures
This means that either the remote side is configured for key auth only, OR your client side may be attempting to auth using mulitple keys, and that exceeds the amount of attempted authorizations on the remote ssh server.
If the issue is trying to auth too many times which ssh defaults to sending the keys to, you ca........
If you are using mint, delete the preference that stops snap from installing (as it is required for lxc)
sudo rm /etc/apt/preferences.d/nosnap.pref
1. Install lxd:
sudo apt install lxd
Issues install lxd or errors? Click here
Debian at this time does not have lxd so you'll need to use snap:
sudo apt in........
The Linux Mint team has disabled it by setting an apt preference, you can edit or just remove the file:
sudo apt install snapd
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package snapd is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source........
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 below appears at first to be a bad mirror DNS error, but if you've ruled that out you just need to clear your broken yum cache and things will be good.
yum update
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: centos.01link.hk
* extras: centos.01link.hk
* updates: centos.01link.hk
http://mirror.worria.com/centos/7.8.2003/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not........
I have a Canon MF642c and the scanner wouldn't work. I tried to use saned but it didn't work with the BJNPlike it did for some other Canon models.
Introducing sane-airscan with packages for the most common distributions: https://software.opensuse.org/download.html?project=home%3Apzz&package=sane-airscan
http........
I was using a small box as a router and one of the ports started going off and coming back at 100M. I truly believe it is simply that it was a case of overheating. Although CPUtemps were only about 67 degrees, the physical box itself was almost burning hot. Isolved the cooling issue and never had the issue again.
Jul 28 15:09:27 swithbox kernel: e1000e: eth1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
Jul 28 15:09:28 swithbox kernel:........
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........
Iam going to build this based on a series of small howto QEMU / KVMposts I've made as I feel much of the information is actually hard to find and piece together from the rest of the web.
What I'm going to focus on is how to use virtio as the NIC because if you don't you get very slow NIC speeds but with the virtio NIC model you basically get host speeds.
/usr/libexec/qemu-kvm -enable-kvm -smp 8 -m 16000 -net user -net nic,model=virtio -drive file=ubuntu-gpt2l........
yum -y install wget unzip
wget https://download.nextcloud.com/server/releases/nextcloud-18.0.2.zip
unzip nextcloud-18.0.2.zip
yum -y install php php-mysqlnd php-json php-zip php-dom php-xml php-libxml php-mbstring php-gd mysql mysql-server
Last metadata expiration check: 0:58:02 ago on Fri 13 Mar 2020 02:12:49 PM EDT.
Dependencies resolved.
===================================================================........
If you are getting this error it is usually caused by having more than 5 keys in your ".ssh" directory. It is a bit of a bug and this is how it manifests itself.
You will find at this point that you are not given any chance to enter a password, or if you are using key based auth that the same thing happens. You'll also find that this is happening with ALLservers you try connecting to.
The solution is to move away key pairs from .ssh so that there ar........
Create your netplan file
vi /etc/netplan/01-netcfg.yaml
network:
version: 2
renderer: networkd
ethernets:
ens3:
dhcp4: no
........
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
........
If you don't aleady have it, you'll need EPEL
Install LXC
yum -y install lxc lxc-templates
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.it.ubc.ca
* epel: mirrors.kernel.org
* extras: mirror.it.ubc.ca
* updates:........
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........
You can do other things but this particular script is just to set all AMD cards to 80% fan speed (remember this script needs to applied everytime you reboot). You could set it is a cron or just throw it into /etc/rc.local
basepath=/sys/class/drm
for hwmon in `ls -1 /sys/class/drm|grep card[0-99]$`; do
echo card=$hwmon;
hwmonname=`ls $basepath/$hwmon/device/hwmon|grep hwmon[0-99]`
hwmonpath=$basepath/$hwmon/device/hwmon/$hwmonname
echo "ec........
[root@localhost:~]
BootModuleConfig.sh echo host-ind nfcd........
[root@thetor2017 conf]# service httpd restart
Stopping httpd: [ OK ]
Starting httpd: WARNING: MaxClients of 3000 exceeds ServerLimit value of 300 servers,
lowering MaxClients to 300. To increase........
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........
We all know Linux is known for good memory management but is it really? It seems all on its own with hardly anything running that you can come back in days or weeks and find that almost all of your RAMis used!
And many will say "no don't worry it's buffers for optimization" but it doesn't seem to help because what is in buffers is not available to use for new programs running or ones that allocate more RAM as far as Ican tell.
The reason Iknow........
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........
#mount the VCSA DVD
mount /dev/sr0 /mnt/cd
#alternatively you could mount the iso directly
mount -o loop vcsa.iso /your/mount/path
#for this purpose we are using the CLI installer on Linux
cd /mnt/cd/vcsa-cli-installer/lin64
#no it's not going to be that easy you can't just run vcsa-deploy like that you need to use a template or configured .json file
./vcsa-deploy
Usage: vcsa-deploy [-h] [--version] [--supported-deploymen........
This happens because Dovecot limits the maximum IMAPconnections per IPto just 10. This may be fine for a single client side IPbut if an entire office or multiple users are behind one IPor a single heavy user is active then you will get bizarre errors in your e-mail clients such as "Password Incorrect" or similar in Thunderbird. It won't be obvious on the client side as to what the problem is and they will probably just think the server is misconfi........
This is not the normal "black screen"issue and I was shocked to eventually find out why. The normal advice of reconfiguring Xorg didn't work. Even booting into "Recovery Mode" did not help.
Here is the short end of the stick that fixed it:
sudo apt-get install mdm mate-desktop-environment
Yes you got it right, mdm and the mate-desktop-environment / gnome were somehow uninstalled. This must be whe........
It looks like this has something to do with APIC but I am not sure. I have similar CPUs with a different MB and BIOS that work fine on the same type of kernel. A lot of time the issue is because of the C-step setting in the BIOS.
The same thing happened on the 2.6 kernel with Centos 6 but this is a homebrew 4.4 kernel soI am not sure why it is happening when even Centos 7 (3.2) kernel works OK.
Solution - It comes down to the BIOS set........
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........
You are using Centos 5 which is deprecated so nothing in yum will work until you follow this post to use the vault:
http://realtechtalk.com/Centos_59_Working_Vault_Repo_file-1921-articles
yum update
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* epel: fedora-archive.ip-connect.vn.ua
Traceback........
Just a note before you do this you should have a sure, guaranteed way into the system such as local, KVMor preferably publickey making bruteforce SSH absolutely impossible since there is no password to bruteforce and even if someone knew the password they wouldn't be able to login except from the local console (presumably you should make sure no one unauthorized has physical access).
1. Edit /etc/ssh/sshd_config
Find the section like this:........
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 ........
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........
This is a VIA made VL805 USB 3.0 Chipset with 4-ports and MOLEX powered. First of all this unit was cheap at about only 9 USD with fast shipping. My biggest concern was if this was a quality unit and would it really give you full USB 3.0 speeds (some people reported with similar cards that for some weird r........
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?........
Ijust use "ufraw" and it does the trick perfectly. Now Iwish I could figure out how to batch convert them into .jpg with ImageMagick (it seems support for .raw is not guaranteed or it has to be compiled in).
apt-get install ufraw........
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was
12: Timeout on http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os: (28, 'Operation too slow. Less than 1 bytes/sec transfered the last 30 seconds')
Error: Cannot find a valid baseurl for repo: base
You would think this should be fine and simple like using a proxy with most other software?
However........
Many users still are not aware but simply patching OpenSSL does not secure you against many known and easy to exploit attacks that will render your encryption useless by an attacker.
Use the following setings in /etc/httpd/conf.d/ssl.conf
SSLCipherSuite "EECDH+ECDSA+AESGCM EECDH+aRSA+AESGCM EECDH+ECDSA+SHA384 EECDH+ECDSA+SHA256 EECDH+aRSA+SHA384 EECDH+aRSA+SHA256 EECDH EDH+aRSA !CAMELLIA !SEED !3DES !RC4 !aNULL !eNULL !LOW !MD5 !EXP !PSK !........
# yum -y install qemu-kvm
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.lzu.edu.cn
* elrepo: ftp.utexas.edu
* epel: ftp.jaist.ac.jp
* extras: mirrors.aliyun.com
* openvz-kernel-rhel6: mirror.fdcservers.net
* openvz-utils: mirror.fdcservers.net
* updates: mirrors.nwsuaf.edu.cn
Resolving Dependencies........
The only way I've found in mdadm to make 2 drives perform like a proper RAID 1 (eg. the read speed should be 2x that of a single drive) is to use the --layout=f2 (far 2).
mdadm raid10 performance issues.
Be very aware that mdadm seems to default to layout=n2 (which means near). In this scenario it means it is like mdadm RAID 1 performance (you get maximum read speeds of a single drive).
dd if=/dev/md126 of=/dev/null bs=1M cou........
Now many people report this card simply not working in various Linux distros and kernels. My issue is different, it always works at 100mbit (eg. plugged into a 100mbit switch) but no matter what 1000M/gigabit switch I would try, it would never work.
The link would be up (the lights were on) and the OS detected the link as being up as well but it wouldn't work at all and could not pass data in or out (not even a ack/ping).
There is one simple solution and command........
vzkernel-2.6.32-042stab116.2.x86_64.rpm&n........
It all comes down to a bug essentially where you are running an older kernel that doesn't support the newer Debian templates. The solution is to update your OpenVZ kernel.
Here are some symptoms of the problem/lack of kernel support:
Ubuntu Template 12.04 requires a manual network start:
service networking start
sshd will not start:
/usr/sbin/sshd
PRNG is not seeded
mknod /dev/random c 1 8........
When you start uploading larger images in Wordpress you have to make sure your maximum attachment size is large enough and that the execution time is not too short:
Uploading
Error
HTTP error.
[Thu May 12 16:32:25 2016] [error] [client 10.10.5.2] PHP Fatal error: Maximum execution time of 30 seconds exceeded in /httpdocs/blog/wp-includes/class-wp-image-editor-gd.php on line 182
Solution Edit p........
This can happen because port 80 is not open, or your license has expired and/or your IP is out of date and also if the license server itself from cPanel is having issues.
In most cases as long as you have a valid license the following command will solve it:
/usr/local/cpanel/cpkeyclt
Updating cPanel license...Done. Update succeeded.
Building global cache for cpanel...Done
Cannot........
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/........
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........
Iwas surprised to see that Linux Mint at the latest 17.2 version still has NO mdadm installer option, and worse the installer will not be able to create a proper booting environment even when you do install it.
How to setup mdadm in Linux mint LiveCD
sudo su
apt-get install mdadm
# partition as you need and then create your mdadm devices
# create your SWAP md0
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /d........
freshclam
ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!).
ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log).
Tue Oct 13 13:49:35 2015 -> WARNING: Incremental update failed, trying to download daily.cvd
Tue Oct 13 13:49:35 2015 -> WARNING: Can't download daily.cvd from db.local.clamav.net
Tue Oct 13 13:49:35 2015 -> Trying again in 5 secs...........
sudo apt-get install zoneminder
[sudo] password for one:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libuser-perl python-evince kdebase-apps kwrite unixodbc
libgnomeprint2.2-data python-soappy vgabios python-metacity hddtemp
python-mediaprof........
mdadm --create /dev/md1 --level 10 --raid-devices=2 /dev/sdb2 /dev/sdc2 --layout=f2 --metadata=0.90
Note that layout=f2 or layout=n2 is very important as without it you'll get a complaint like this:
mdadm --create /dev/md0 --level 10 --raid-devices /dev/sdb1 /dev/sdc1 missing missing
mdadm: invalid number of raid devices: /dev/sdb1
It is basically more like a prop........
An error occurred during a connection to site.com. SSL received a record that exceeded the maximum permissible length. (Error code: ssl_error_rx_record_too_long)
The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Please contact the website owners to inform them of this problem.
When the above happens in our experience it is a misconfiguration of........
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........
Have you ever tried to run a command like rm to delete several hundred thousand files? Iam not sure what the limit is but any time it is exceeded you need to use a work around like below (which will delete any number of files).
Solution
find . -maxdepth 1 -name "*.*" -print0 | xargs -0 rm........
#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........
yum -y install mathtools
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: centos.mirror.rafal.ca
* epel: mirror.steadfast.net
* extras: mirror.agmn.ca
* rpmforge: repoforge.mirror.constant.com
* updates: centosb5.centos.org
extras ........
./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........
This can happen when you install RPMForge or other repos with the wrong architecture and here's how you fix it (simply uninstalling won't usually fix it):
solution
yum clean all
yum -y install openvpn
Loaded plugins: fastestmirror, presto
Loading mirror speeds from cached hostfile
* base: mirror.its.sfu.ca
* extras: centos.mirror.nexicom.net
* rpmforge: mirror.cpsc.ucalgary.ca
* up........
It's not as simple as "yum install" as you can see below and it doesn't stop there.
yum install php53
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* rpmforge: mirror.us.leaseweb.net
* extras: centos.mirror.rafal.ca
* updates: centos.mirror.nexicom.net
* base: centos.mirror.nexicom.net
* addons: centos.mirror.nexicom.net
Setting up Install Process........
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 units in echo are kB as in kilobyte.
Setting a high sync speed
echo 120000 >/proc/sys/dev/raid/speed_limit_min
This will increase the speed, note that sometimes a rebuild is slow due to current disk activity/iowait.
If that is not the cause then you may have a hardware issue (controller, cable or a bad drive).
Setting a lower sync speed
echo 1200 >/proc/sys/dev/raid/speed_limit_max........
/scripts/phpextensionmgr install PHPSuHosin
Updating md5sum list
Fetching http://httpupdate.cpanel.net/cpanelsync/easy/targz.yaml (connected:0).......(request attempt 1/12)...Resolving httpupdate.cpanel.net...(resolve attempt 1/65)...
Fetching http://httpupdate.cpanel.net/mirror_addr_list (connected:0).......(request attempt 1/3)......connecting to 74.50.120.123...@74.50.120.123......connected......receiving...100%......request success......Done........
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........
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........
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 ........
The error itself "mkdir(): Too Many Links" is not very useful, but I'll translate it into plain English.
It means you've reached the filesystem's limit of how many directories can be created in a single directory.
In this case for ext3 the limit is 32000 and it was exceeded.
What's the solution?
The simple solution is to move those directories into more subdirectories possibly sorting them by date, alphabet or numerically.........
This is just trying to read 5GB off the drive with dd and the drive initially tested ok but shortly after I wondered why I was seeing 2MB/s read speeds. Notice the "current_pending_sector", anytime I've seen it at anything above 0 even with no other bad fields/attributes, it means the drive is bad.
ata1.00: exception Emask 0x0 SAct 0x3 SErr 0x0 action 0x0
ata1.00: irq_stat 0x40000008
ata1.00: failed command: READ FPDMA QUEUED
ata1.00: cmd 60/00:00:........
Client Log
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 192.168.1.253 [192.168.1.253] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type 1
debug1: identity file /root/.ssh/id_d........
vzquota : (warning) block_hard_limit [102] < block_current_usage [520824]
This is because your disk usage of the container exceeds the quota.
Eg. once on a test container I had accidentally set it to 32MB yet the OS took about 600MB.
Just set the quota to something bigger than the currently used space to solve it.
vzctl set 3891 --diskspace 5G:5G --save........
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........
I've read some people/sources say "the timing must match or it won't work". This is not true at least for the Supermicro boards I've tested this on.
Some examples:
PC2-5300F-555-12
PC2-5300F-555-11
etc.. Notice the "12" and "11"
Also the ones that have a "PC2-5300F-555-11-B0" or "PC2-5300-555-11-D0" are also fine.
What happens is what one would expect, the........
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........
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........
The size of the message you are trying to send exceeds a temporary size limit of the server. The message was not sent; try to reduce the message size or wait some time and try again. The server responded: 4.5.3 Error: too many recipients.
We set this in main.cf:
smtpd_client_recipient_rate_limit=0
We didn't specify it before and the default is said to be 0/unlimited and it still didn't change anything.........
This may sound silly but there will be conflicts/issues with the default Centos repository so you have to use a third party like remi (I prefer not to do this but it's the only option unless you migrate your sites/data to another server or can stand some downtime-not an option IMHOon a production server).
You may need to upgrade to PHP5.3 to run Joomla or many other reasons.
Your host needs to use PHP 5.2.4 or higher to run this version of Jo........
Could not display "trash:///".
Error: DBus error org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
Please select another viewer and try again.
This happened in Ubuntu but only because I was trying to delete millions of files at once and i........
I experienced this with CPanel's Exim after an auto-update (a Google of this error produces lots of complaints with few clear solutions). In this case I'll put the solution at the top.
Run /scripts/buildeximconf to rebuild the Exim config and it should be fine after that.
mail -vs "from test" user@dest.com < .bash_history
LOG: MAIN
cwd=/root 4 args: send-mail -i -v user@dest.com
LOG: MAIN
&........
I really am a Linux fan but my comments here may not show it. Although I'm quite familiar with Linux CLI to administer servers, I find Linux GUI OS's like Ubuntu at times very clunky.
This is partially because there's no such thing as a "self-made" Linux from scratch where the UIwas designed by a single team. Linux is made up of several different projects that are generally completely separate and this lack of integratiion is a key issue that makes things f........
It really is as simple as:
cdrecord -v dev=/dev/sr0 pathtoyourisoimage.iso
-v is for verbose, I prefer it but if you don't you won't see as much output like below (I like to know the details and exactly what's happening)
dev=/dev/sr0 specifies the device name of your burner (they say not to use it and to specify some weird annoying device string but using the raw /dev has always worked for me and is how it should have been implemented from the start IMHO)........
I am watching the Canucks riot and a reporter said Twitter is down.
My home connection on Shaw is fine, but when Iused my Rogers network over the cell, it says "Rate Limit Exceeded". I wonder if this is a transparent redirect by Rogers under police order?
I noticed that the Telus network loaded Twitter just fine.........
It's weird because I have a nearly identical box and setup and I can update the ovzkernel-PAE* just fine but on this box it doesn't work.
I only get this error with the openvz.repo and not others such as Centos-Base.repo
With my other server it works normally:
================
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package ovzkernel-PAE.i686 0:2.6.18-238.12.1.el5.0........
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........
yum -y install vnstat
chown nobody.nobody -R /var/lib/vnstat/
#replace venet0 below with your desired interface
sudo -u nobody vnstat -u -i venet0
#edit: vi /etc/sysconfig/vnstat
#VNSTAT_OPTIONS="-i venet0"
# only use the sed below if you are using venet0 instead of eth0 or replace accordingly
sed -i 's/eth0/venet0/g' /etc/sysconfig/vnstat
[root@monitor]# yum install vn........
This happened during a RAID array check:
SMART says both drives pass the test, but I'm doing a long test on them and hopefully this is not a hardware error.
Apr 3 04:22:01 remote kernel: md: syncing RAID array md2
Apr 3 04:22:01 remote kernel: md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc.
Apr 3 04:22:01 remote kernel: md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reconstruction.
Apr........
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........
There are all kinds of threads and links on the internet, and this seems to be a contentious issue butI don't know why.
95th percentile is either a good deal for some or a big rip off for others, Ijust said it there :)
But the reality is that for MOST people who transfer low amounts of data but burst to higher speeds such as 40mbit+ even for short periods of time, then you'll pay a lot of money to do that.
Basically 95th percentile is an-old archaic method........
find what MPM Apache is using, it will either be using "worker" or "prefork"
apachectl -l
Compiled in modules:
core.c
prefork.c
http_core.c
mod_so.c
In my case it is "prefork"
vi /etc/httpd/conf/httpd.conf
Find the section that looks like this (by default one will normally exist for prefork and for worker, but in my case I only care a........
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........
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........
Jan 16 04:02:03 centosbox syslogd 1.4.1: restart.
Jan 16 04:07:34 centosbox kernel: INFO: task updatedb:20771 blocked for more than 300 seconds.
Jan 16 04:07:34 centosbox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Jan 16 04:07:34 centosbox kernel: updatedb D F78BE050 6476 20771 20766&n........
This made me nervous but it's clearly a cronjob based on the messages log that happens every Sunday at about 4:22.
I actually can't find any evidence of it in cron.d cron.daily but it is there somewhere obviously.
What I don't get is why doesn't this cronjob do a datacheck like Ubuntu's cronscript does? When you unnecessarily rebuild the array you lose your redundancy during that point which makes your data extremely vulnerable.
*Update I did a grep of &q........
This doesn't seem to be widely known (maybe it's in some documentation that none of us read though)but there's an easy way to check the integrity of any mdadm array:
sudo echo check > /sys/block/md0/md/sync_action
-bash: /sys/block/md0/md/sync_action: Permission denied
sudo will never work, this only works as root since echo is not actually a binary/command. It is built-into bash.
/sys/devices/virtu........
Install the "Editors" and "Net" groups that will give you rsync, ssh, ssh-keygen and cron.
The trickiest thing that I keep forgetting about each time is you have to run "cron-config" which adds the cron service to Windows, and without doing that obviously no cron jobs will be run thus making automatic backups impossible.
Warning about rsync/cygwin and using the -a archive switch.
It's a good thing I caught this because it doesn't work ri........
This really made me nervous but notice the mdstat says "check". This is because in Ubuntu there is a scheduled mdadm cronscript that runs everyday on Sunday at 00:57 that checks your entire array. This is a good way because it prevents gradual but unnoticed data corruption which Inever thought of.
As long as the check completes properly you have peace of mind knowing that your data integretiy is assured and that your hard drives are functioning properly (I'........
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........
This is an SFTP mount that does not work or prompt for password.
Error: DBus error org.freedesktop.DBus.Error.ServiceUnknown: The name :1.1127 was not provided by any .service files
Please select another viewer and try again.
It seems to me that the connection often times out after being opened and the application doesn't know how to handle the disconnection and doesn't realize it needs to kill the instance and restart the connection.........
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........
Here is a RAID 1 partition (500GB Seagate & 2TB WD):
Sequential Reads
File Blk Num Avg Maximum Lat%&nbs........
I'm using Ubuntu 8.04 but anyone using older kernels will find this may apply to them. My Intel graphics are very slow with the default Xorg settings but by using "EXA" acceleration, scrolling down windows of text becomes pretty snappy.
Just edit /etc/X11/xorg.conf
Section "Device"
Identifier "Configured Video Device"
&nb........
cat /proc/user_beancounters produces the following:
kmemsize 1861537 5139870 12752512 12752512 26965041
Notice the failcnt "26965041", that is for kmemsize and at first it confused me. The system had enough guaranteed and enough burst RAM available. kmemsize is a variable indepedent of that, but who cars about the explanation right, let's just make thing........
Not sure what rsync switches/options to use?
rsync -PDrphogtl
The short version would be:
rsync -Pha
I think these are really common sense options to use and probaby should be the default.
Explanation of rsync switches
P = display the progress
D = hybrid of --specials and --devices so all special and device files will be copied as well.
r = recursive (otherwise rsync won't copy files deeper than........
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........
rsync bash script
[code:1:722d8a25c1]#!/bin/bash
# config ---------------------------------
# two methods
# from = receive data from another server
# to = send data to another server
rsync_method=from
rsync_ip='192.168.5.18'
local_dir='/home/backupguy/backups'
remote_dir='/home/backup'
free_space_bin='/home/backups/freediskspace.sh'
# config end ------------------------------
if [ '$rsync_me........
Need identd for port 113 ? Install authdyum install authd
Happy identing :)Actually it's not that simple.
It installs as an "xinetd" service and is disabled and turned off by deafult.
To enable it run:
[code:1:8c94df8319]
chkconfig --level 3 auth on
service xinetd restart
[/code:1:8c94df8319]
This will set identd aka authd to start by default.
service xinetd resta........
Quick Tutorial On Starting A Web Site[b:3cef3c01b6]Step 1.[/b:3cef3c01b6] Purchase a Domain Name (eg. yoursite.com)
[b:3cef3c01b6]Step 2.[/b:3cef3c01b6] Design your site using a program such as Microsoft Frontpage or Macromedia Dreamweaver. If you are unable or unfamiliar with doing this you may want to hire a company to create your site (many of them will handle each aspect of setting up your site).
[b:3cef3c01b6]Step 3.[/b:3cef3c01b6] Host your site........
Become your own ISP!http://waverider.com/
I would link to the exact product I am mentioning but it's under Products/5.8Ghz because I can't find the exact URL because of their annoying javascript and frames (you'll see what I mean).
The exciting thing is that this unit can supposedly be up to 72mbit, it is NOT line of sight and the range is up to 20miles. I wonder how real world speeds and range would actually be and if it is reliable.
I j........
Canada Net SpeedWhat is the fastest internet I can get in Canada?A lot of ISPs offer 10mbit cable such as Cogeco or some other one in Halifax I think. I can't remember the name.
Right now cable internet will offer the fastest.........
NEC ND-3500A is great!I just picked up an NEC 3500A a few weeks ago and I love it.
It is a great all in-one optical drive solution.
It can burn DVD/+R-R at up 16x, read at 16x and rewrite at 4x and CD-R at up to 48x!
Not bad, but the impotant part is that it delivers consistent high quality burns and the drive is as quiet as I could ask it to be.
It's also convenient that it has a lot of hacked firmware for overspeeding of........
Load Balancing/ClusteringAn interesting article that discusses the pros, cons and viability of load balancing/clustering
http://www.wwwcoder.com/main/parentid/493/site/4189/68/default.aspx
ZoneEdit seems to offer an interesting Fail Over Service as well:
http://www.zoneedit.com/doc/faq.html#fo........
This really is a difficult and confusing process for non-Mandarin speakers, but here's what I've done and learned so far:
You can purchase an "M-Zone" China Mobile pre-paid SIMCard from almost anywhere but I tried to purchase mine from Suning (a large electronics dealer) hoping they would be able to help me or answer my questions but my plan didn't work out at all. At Suning once I found someone who spoke some English they gave me the 55 RMB M-Zone China Mobile P........
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........
Have you ever seen this dreaded message in your Apache/HTTPD /var/log/httpd/error_log?
[error] server reached MaxClients setting, consider raising the MaxClients setting
The error itself is slightly misleading. Ibelieve this happened to one of my servers, I found Apache was running still, and that you could telnet to port 80 but no respnose would be given.
For some reason my error log initially did not have the above error, but after a restart I saw........
A VPS Server I had just wasn't working right, code that I migrated there just wasn't working. For example, it kept telling me the connection to the database was unsuccessful, halfway through iterating through results it already had.
Then I realized it wasn't my code. Ichecked my /proc/user_beancounters and found this:
cat /proc/user_beancounters
Version: 2.5
uid resource held maxheld barrier limit failcnt........
I've had an old Blackberry for a few years and I was ready to spend some serious cash on a nice Nokia. I love the idea of the Linux based Symbian S60 OS, so I was looking at phones like the E63, E71 (both are basically the same, at least CPU/screensize although E71 is thinner, has a 3MP camera, has GPS, and has dedicated buttons to adjust the volume).
Then Iheard about the N97 and what a revolution it was supposed to be and it was even compared to iPhone.
To........
This is the Intel Atom 330 motherboard with integrated Realtek Gigabit NIC (Intel Desktop Board D945GCLF2 Motherboard W/ Atom 330 1.6 GHz Dual Core Processor - Mini-ITX)
I cannot achieve more than 15 MB/s, even doing a local transfer through eth0 to it's own IP.
100% 95MB 15.9MB/s 00:06
So this is not a cabling, switch or hardware issue, it seems like a driver or chipset limitation problem.
Here is my........