Docker Tutorial HowTo Install Docker, Use and Create Docker Container Images Clustering Swarm Mode Monitoring Service Hosting Provider

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.........

Scanner not working in Linux Ubuntu Fedora Mint Debian over the network? Use sane-airscan!

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........

OpenVZ vs LXC DIR mode poor security in LXC

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........

ssh how to connect using a SOCKS 5 proxy with nc and proxycommand

This is not about using ssh as a proxy, but rather, using a proxy when you are SSHing to another host and using ProxyCommand (where we normally use nc as our proxy tool). In newer versions of nc the syntax has changed to the following: ssh -o ProxyCommand="nc -x 127.0.0.1:1234" %h %p user@host The format must be like above in newer nc versions. Just be sure to change the 1234 to the port of your SOC........

qemu-kvm qemu-system Image format was not specified for '/mnt/space/cucm12.img' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'ra

WARNING: Image format was not specified for '/mnt/space/cucm12.img' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'raw' format explicitly to remove the restrictions. #you should manually specify the format q........

How to install and setup LXC Containers (OpenVZ alternative) on Centos 6 / 7

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:........

How To Boot Cisco CUCM UCSInstall 8.6, 10, 11 and 12 on KVM/Proxmox

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........

systemd management using systemctl and journalctl to check systemd logs

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........

OpenVZ container will not stop Child 546246 exited with status 1

vzctl stop 4096 Removing stale lock file /vz/lock/4096.lck Stopping container ... Child 546213 exited with status 1 ^Z [1]+ Stopped vzctl stop 4096 ~]# rm /vz/lock/4096.lck rm: remove regular file `/vz/lock/4096.lck'? y ~]# vzctl stop 4096 Stopping container ... Child 546246 exited with status 1........

vzquota : (error) Quota on syscall for id 4532: No such file or directory vzquota on failed [3] OpenVZ Error and Solution

Starting container... vzquota : (error) Quota on syscall for id 4532: No such file or directory vzquota on failed [3] Solution vzquota drop 4532 Then start the container and it should work. It actually happened after migrating the VPS manually to ano........

OpenVZ Solutions vzquota : (error) Can't open quota file for id 123123, maybe you need to reinitialize quota: No such file or directory

Error: Unable to apply new quota values: quota not running Container start failed (try to check kernel messages, e.g. "dmesg | tail") Killing container ... Container was stopped Error: Unable to apply new quota values: quota not running Can't umount /vz/private/123123: Invalid argument [root@rtt 123123]# vzquota on 123123 vzquota : (error) Can't open quota file for id 123123, maybe you need to reinit........

MySQL Cannot Update/Write to any database table solution

This happened on Centos for no apparent reason with no obvious issue in the logs. Data could be read fine but not written (possibly due to some corruption or out of memory issue in the OpenVZ container is the best guess). All mysql update and insert queries failed freezing without any error log on any database and table. Tried to restart: service mysqld restart Timeout error occurred trying to stop MySQL........

OpenVZ error : Container start failed (try to check kernel messages, e.g. "dmesg | tail") Locked by: pid 166638, cmdline vzctl start 888171

This container won't start after exhausting its memory. There are no relevant or helpful messages in dmesg or vzctl.log as well. Standard troubleshooting such as disabling PPP etc has not helped. 2017-07-06T23:33:29-0400 vzctl : CT 888171 : Locked by: pid 166029, cmdline vzctl start 888171 2017-07-06T23:33:29-0400 vzctl : CT 888171 : Container already locked 2017-07-06T23:33:29-0400 vzctl : CT 888171 : Container was stopped 2017-07........

PYCURL ERROR 22 - The requested URL returned error: 404 Not Found Solution

# 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........

OpenVZ mass ip update

The file ipupdate.txt should look like this: ip.ip.ip.ip ctid while read -r; do ip=$REPLY setip=`echo $ip|awk '{print $1}'` ctid=`echo $ip|awk '{print $2}'` echo "vzctl set $ctid --ipadd $setip --save" vzctl set $ctid --ipadd $setip --save done < ipupdate.txt........

OpenVZ Solution CPT ERR: c02fa000,73 :CPT: lock fd is closed incorrectly: 1 and vps-net_add ERROR: Unable to add route ip route add 192.168.5.2 dev venet0

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........

grubby fatal error: unable to find a suitable template solution Centos

vzkernel-2.6.32-042stab116.2.x86_64.rpm&n........

OpenVZ Migration Hostnode Containers from Centos 5 to Centos 6

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........

OpenVZ Error: Failed to load 2nd level quota solution

Syncing private Live migrating container... Syncing 2nd level quota 11000: invalid option -- F Usage: vzdqload quotaid [-c file] commands Loads user/group qouta information from stdin into quota file. -c file use given quota file Commands specify what user/group information to load: -G grace time -U disk limits........

Openvz error solutions Container already locked (error) can't lock quota file, some quota operations are performing for id 1200

rm /vz/lock/1200.lck rm: remove regular file `/vz/lock/1200.lck'? y vzctl start 1200 Container already locked vzctl start 1200 Starting container ... vzquota : (error) can't lock quota file, some quota operations are performing for id 1200 vzquota on failed [7] vzquota off 1200 vzctl start 1200 vzquota on 1200 root@rttbox ~]# vzquota off 1200 vzquota : (........

possible SYN flooding on port 80. Sending cookies.

Errors like this are shown on high usage servers and ports so it is common to see it on http and even imap ports: possible SYN flooding on port 80. Sending cookies. The Linux kernel will even detect flooding on OpenVZ containers: possible SYN flooding on ctid 6000, port 993. Sending cookies. In many cases this is not an issue and is more so simply a result of regular, but high usage traffic.........

Openvz kernel: [10186978.064405] TCP: time wait bucket table overflow (CT3)

kernel: [10186978.064405] TCP: time wait bucket table overflow (CT3) Varying opinions are out there but in general it seems like the most common culprit is a lack of privvmpages, with a modern OpenVZ system the best way is to set privvmpages as equal to what your RAM is and this has resolved the messages on another system. If it's truly a TCP issue you can adjust the following parameters:........

Ubuntu/Debian OpenVZ Template Problems No Networking and SSH not starting

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........

iptables: Applying firewall rules: iptables-restore: line 40 failed

service iptables start iptables: Applying firewall rules: iptables-restore: line 40 failed [FAILED]........

OpenVZ how to enable FUSE in the container

vzctl set 2 --devnodes fuse:rw --save Where "2" is the ctid........

Debian 8 Jessie in Linux OpenVZ Container does not work on Centos host

It sounds like this is corrected in later versions of the OpenVZ kernel but Iam not sure, it may also be that a much newer kernel is needed and Centos may not have a recent enough kernel. *Debain 7.0 however does work fine as a temporary fix or work around. Debian 8 OpenVZ no IP and networking not working: lo Link encap:Local Loopback ........

How to manually save bash history

This is useful in the case you are not properly logged in via an OpenVZ session or even a normal SSH session that you fear may go down(if the connection is broken the history is not saved). Save your bash_history like this: history -w ~/.bash_history You can always change the above to another file eg /tm........

openvz yum problem Centos 6.5 cannot find file on mirror:

#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 ........

OpenVZ Install Guide Again / Quick Setup

yum -y install wget wget -P /etc/yum.repos.d/ http://ftp.openvz.org/openvz.repo rpm --import http://ftp.openvz.org/RPM-GPG-Key-OpenVZ yum -y install vzkernel vzctl #enable ip_forward sed -i s/'net.ipv4.ip_forward = 0'/'net.ipv4.ip_forward = 1'/g /etc/sysctl.conf #all interfaces should not send redirects echo "net.ipv4.conf.default.send_redirects = 1" >> /etc/sysctl.conf echo "net.ipv4.co........

Openvz Enable netadmin

vzctl set $CTID --devnodes net/tun:rw --capability net_admin:on --save........

OpenVZ vzctl update changes how iptables work - iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. updated solution

Are you getting the same old error message even though your iptables settings for OpenVZ are correct? iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. The reason is because in newer vzctl the old way of setting IPTABLES="" in vz.conf is completely deprecated (I spent some time fiddling wondering why my settings were correct but........

Directadmin compile error solution cc: Internal error: Killed (program cc1)

cc: Internal error: Killed (program cc1) Please submit a full bug report. See for instructions. make: *** [ext/fileinfo/libmagic/apprentice.lo] Error 1 make: *** Waiting for unfinished jobs.... Stopping crond: ........

OpenVZ Howto disable ploop and switch back to SIMFS

It's simple, just edit /etc/vz/vz.conf and add or change the following: VE_LAYOUT=simfs........

Openvz iptables v1.4.7: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. solution

iptables -t nat -A PREROUTING -p tcp -m tcp -d 192.168.2.1/32 --dport 3389 -j DNAT --to-destination 192.168.5.2:3389 iptables v1.4.7: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. The above is often because you don't have the correct modules loaded on the hostnode or enabled for the container but in some cases it's actually a weird openvz setting. Che........

Openvz 2014-08-12T19:05:55-0400 vzctl : CT 391801 : Unable to start init, probably incorrect template 2014-08-12T19:05:55-0400 vzctl : CT 391801 : Container start failed

2014-08-12T19:05:55-0400 vzctl : CT 391801 : Unable to start init, probably incorrect template 2014-08-12T19:05:55-0400 vzctl : CT 391801 : Container start failed This was caused by trying to run a 64-bit template on a 32-bit kernel hostnode which is obviously impossible. The solution is to use a 32-bit template or upgrade the hostnode to 64-bit.........

OpenVZ Unable to stop container

vzctl stop ctid Killing container ... Child 1033348 exited with status 7 Unable to stop container vzctl enter ctid enter into CT 29831 failed Some have suggested using vzctl stop ctid --fast which does not work. The only thing that seems to work is restarting the vz service.........

drbd won't sync 8.3.13 on OpenVZ kernel

I used the matching 8.3.13 utilities and it didn't work but strangely the newer 8.3.16 which makes DRBD complain works just fine. GIT-hash: 83ca112086600faacab2f157bc5a9324f7bd7f77 build by root@sighted, 2012-10-09 12:47:51 0: cs:SyncSource ro:Secondary/Primary ds:UpToDate/Inconsistent A r----- ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5236960 &am........

Openvz Can't load ploop library: libploop.so: cannot open shared object file: No such file or directory

Can't load ploop library: libploop.so: cannot open shared object file: No such file or directory The above happens when you haven't installed the ploop tools: yum -y install ploop........

OpenVZ avoid vzctl 4.7 and ploop

OpenVZ has made vzctl version 4.7 default to using ploop which is a big annoyance. No one wants it otherwise we'd use Xen or KVM. Make sure to manually specify vzctl 4.6.1 or you will have issues with old scripts breaking since it defaults to using ploop (a single image like Xen/KVM). Here's a list to old versions of vzctl.........

yum error "Error: database disk image is malformed" solution

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 ........

OpenVZ mismatched kernel and dev when compiling.

./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........

OpenVZ Quick Install Copy & Paste for Centos 6

yum -y install wget wget -P /etc/yum.repos.d/ http://ftp.openvz.org/openvz.repo rpm --import http://ftp.openvz.org/RPM-GPG-Key-OpenVZ yum -y install vzkernel vzctl After that just reboot and you may also have to enable ip_forward in /etc/sysctl.conf........

Openvz OOM Centos Issue Memory Config Settings Solution

Linux box13. 2.6.32-042stab076.5 #1 SMP Mon Mar 18 20:41:34 MSK 2013 x86_64 x86_64 x86_64 GNU/Linux even setting privvmpages to a specific setting DOES not affect "free -m" in containers. This is probably a kernel issue 23:36:29 up 159 days, 7:12, 4 users, load average: 0.42, 0.44, 0.33 [root@box13 ~]# free -m total&n........

vzquota : (error) Quota on syscall for id 42131: No such file or directory vzquota on failed [3]

Starting container... vzquota : (error) Quota on syscall for id 42131: No such file or directory vzquota on failed [3] Solution cd /var/vzquota mv quota.42131 quota.42131-disable vzctl start 42131 Starting container... Initializing quota ... Container is mounted Adding IP address(es): Setting CPU units: 1000 Container start in progress... ........

Dell Perc 6/i cannot downgrade

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........

pxe-32 tftp open timeout

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 - Solution

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 ........

Openvz "Container is currently mounted (umount first)" solution

Container is currently mounted (umount first) The container is stuck in the "mounted" state, you must manually start it to get it out of that state (there is no umount option as implied by OpenVZ vzctl).........

OpenVZ Container Can't Restart, stuck in mounted state

When trying to reboot this Centos 5 container, it gets stuck as "mounted" and requires a manual start command, here is what dmesg shows: [424458.173252] VE10000: no allowed mount options found for device 0:21 [424458.177970] proc: unrecognized mount option "relatime" or missing value [424460.297663] CT: 10000: stopped [426663.466433] CT: 10000: started........

vzquota : (warning) block_hard_limit [102] < block_current_usage [520824] - Openvz Solution

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........

Directadmin error/** Found 7 pre-existing rpmdb problem(s), 'yum check' output follows: e2fsprogs-devel-1.41.12-3.el6.i686 has missing requires of e2fsprogs-libs = ('0', '1.41.12', '3.el6') e2fsprogs-devel-1.41.12-3.el6.i686 has missing requires of l

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........

OpenVZ - how to manually restore a VPS from another host or backup

There are 3 pieces that are required to restore and make it work (of course consider if any kernel modules need to re-enabled and if you need to change the IPs): Copy the vz/private/VEID directory to /vz/private Copy the /etc/vz/conf/VEID.conf to /etc/vz/conf/ mkdir /vz/root/VEID After that you should be able to see the VE in vzlist -a You should then be able to start it normally.........

KVM/QEMU Base/Template Images and the power they provide

qemu-img create -b centos.5-8.x86.20120308.qcow2 -f qcow2 ../kvmguests/25000-centos5.8x86.qcow2 Formatting '../kvmguests/25000-centos5.8x86.qcow2', fmt=qcow2, backing_file=centos.5-8.x86.20120308.qcow2, size=10485760 kB -b the source/base image -f format is qcow2 and the location of the destination image What is so special about this? It's even quicker than creating a template with OpenVZ but this is an actual OS. It saves time a........

Centos 5 and OpenVZ won't boot after kernel install

For whatever reason the current OpenVZ yum repo file enables the RHEL6 version of OpenVZ, why is this bad? Because if you're running Centos 5 it still defaults to using the kernel from RHEL6 which won't work on RHEL5/Centos 5. Ionly realized this after wondering why I couldn't boot into OpenVZ that it was using one meant for RHEL6. To fix the problem you have to edit /etc/yum.repos.d/openvz.repo and disable the "[openvz-kernel-rhel6]" section by changing........

setquota: Mountpoint (or device) / not found. setquota: Not all specified mountpoints are using quota. with openvz solution

Directadmin Error when changing user settings/saving Details Error with system Quotas setquota: Mountpoint (or device) / not found. setquota: Not all specified mountpoints are using quota. Debug Guide You have to disable and enable the quota's using vzquota on and off. After that it will work.........

Error: detected vswap CT config but kernel does not support vswap This means either old kernel or bad config (physpages NOT set to 0:unlimited) Solution for OpenVZ

Error: detected vswap CT config but kernel does not support vswap This means either old kernel or bad config (physpages NOT set to 0:unlimited) Solution vzctl set $veid --physpages 0:unlimited --save........

iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) - OpenVZ Container Problem iptables module problem solution

iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) This solution applies to all other iptables modules/problems for OpenVZ, you'll just need to add them to both lists/lines below if you have modules other than what I have below. The modules need to be enabled in both iptables and the OpenVZ hostnode itself and then the containers which need it must be restarted. How To Enable IPTables Modules in OpenVZ........

File /etc/vz/conf/ve-vps.basic.conf-sample not found: No such file or directory - Openvz Error solution

Stuff like this always happens/breaks after a vzctl update, whether it's new parameters being added or required etc.. File /etc/vz/conf/ve-vps.basic.conf-sample not found: No such file or directory Fix the value of CONFIGFILE in /etc/vz/vz.conf Creation of container private area failed Warning: distribution not specified in CT config, using defaults from /etc/vz/dists/default WARNING: /etc/vz/conf/4400.conf not found: No such file or directory........

ifup eth0 SIOCSIFFLAGS: Cannot allocate memory Failed to bring up eth0 Centos Network won't work after kernel update and reboot

ifup eth0 SIOCSIFFLAGS: Cannot allocate memory Failed to bring up eth0 This is on a Centos 5.5 machine with OpenVZ kernel 2.6.18-238.12.1.el5.028stab091.1PAE, I updated 3 systems with the same hardware to the same kernel and for some reason the network didn't come back. This only happened once the first time I booted into the new kernel and hasn't happened again but this is a serious issue for those running systems from remote locations such as a datacente........

Openvz Container IP not working suddenly Solution

This may not apply to everyone but here is what happened to me. One day my IP connectivity for one container went dead, I could ping the hostnode from it and the hostnode could ping it but there was no external routing. I restarted the network service but it didn't help. I checked the routing table inside the VPS and the host and everything looked normal. Iadded another different IPon the same subnet to the container and it worked. Right away I st........

Openvz migration error solution Error: Failed to suspend container CPT ERR: f68cf000,25000 :foreign process 15755/14731(vzctl) inside CT (e.g. vzctl enter or vzctl exec). CPT ERR: f68cf000,25000 :suspend is impossible now.

Starting online migration of CT 25000 to 192.168.5.1 Preparing remote node Initializing remote quota Syncing private Live migrating container... Error: Failed to suspend container CPT ERR: f68cf000,25000 :foreign process 15755/14731(vzctl) inside CT (e.g. vzctl enter or vzctl exec). CPT ERR: f68cf000,25000 :suspend is impossible now. CPT ERR: f68cf000,25000 :foreign process 15755/14731(vzctl) inside CT (e.g. vzctl enter or........

Openvz CPT ERR: cc4c0800,28000 :Unknown image version: 304. Can't restore.

CPT ERR: cc4c0800,28000 :Unknown image version: 304. Can't restore. This happens when you live migrate between OpenVZ servers with different kernels running, at least significantly different by date. There is no solution except to make sure you're running the same kernels on all machines, or at least not kernels that are much older or different (this is just a guess though, you should ensure all kernels are the same).........

Openvz YUM Error Solution to "[Errno -1] Metadata file does not match checksum Trying other mirror."

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........

How to recover from dead DRBD partition/hard drive in two simple commands

This assumes that you've at least created the correct partition for your DRBD already. Notice that I am "diskless", that's because either your DRBD partition doesn't exist/has been renamed (eg. sdb becomes sda when sdb dies and you reboot) or because that drive is really actually dead/gone. *If you need to permanently change the partition/device for your resource be sure to edit /etc/drbd.conf on both hosts and reload the config. (replace r0 with........

Yahoo Mail (email) DNS Server Out Of Date Problems

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........

Openvz Enable TUN/TAP OpenVPN

Make sure the module "tun" is loaded on the host. vzctl set 2000 --devnodes net/tun:rw --save *Note what's below is what OpenVZ says you need (but I've never had to do it) vzctl exec 2000 mkdir -p /dev/net vzctl exec 2000 mknod /dev/net/tun c 10 200 vzctl exec 2000 chmod 600 /dev/net/tun On the container test the device: when Something is wrong:........

Openvz Disk quota exceeded inode problem with free space

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........

yum in Centos 5/Xen halts and exits suddenly

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........

vzquota : (warning) Incorrect quota shutdown for id 2333, recalculating disk usage vzquota : (error) quota check : lstat `sess_a5078fce5f569e453ab1fb39b0fc69f8': No such file or directory vzquota on failed [1]

first container would not come up: Starting CT 2333: service vz stop OpenVZ is locked [FAILED] 2010-11-29T23:26:23-0800 vzctl : CT 2333 : Starting container ... 2010-11-29T23:37:21-08........

Initializing quota ... Error: Not enough parameters, diskinodes quota not set

Initializing quota ... Error: Not enough parameters, diskinodes quota not set vzctl set $veid --diskinodes 90000:91000 --save New versions of OpenVZ seem to have some strange diskinodes parameter which is required.........

Openvz Error Starting OpenVZ: failed to load module vzmon [FAILED]

service vz start Starting OpenVZ: failed to load module vzmon [FAILED] vzmon: Unknown symbol ve_snmp_proc_init vzmon: Unknown symbol addrconf_sysctl_free vzmon: Unknown symbol ve_ndisc_init vzmon: Unknown symbol addrconf_ifdown vzmon: Unknown symbol ip6_frag_cleanup vzmon: Unknown symbol fini_ve_route6........

OpenVZ: failed to load module vzmon [FAILED] vzmon: Unknown symbol ve_snmp_proc_init vzmon: Unknown symbol addrconf_sysctl_free vzmon: Unknown symbol ve_ndisc_init vzmon: Unknown symbol addrconf_ifdown vzmon: Unknown symbol ip6_frag_cleanup vzm

Openvz Quick Install for CentOS 5 Tutorial

cd /etc/yum.repos.d wget http://download.openvz.org/openvz.repo rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ yum install ovz-kernel-PAE Now remember to set /etc/sysctl.conf to "net.ipv4.ip_forward = 1" You can apply the change immediately by running sysctl -w net.ipv4.ip_forward = 1 but remember that you still have to set sysctl.conf sysctl -p will load and apply any changes to s........

Openvz Live Migration Error - Error: undump failed: Invalid argument Restoring failed: Error: iptables-restore exited with 2 Error: Most probably some iptables modules are not loaded Error: rst_restore_net: -22

Adding IP address(es): 192.168.5.8 192.168.5.9 Setting CPU units: 1000 Error: undump failed: Invalid argument Restoring failed: Error: iptables-restore exited with 2 Error: Most probably some iptables modules are not loaded Error: rst_restore_net: -22 Container start failed Stopping container ... Container was stopped Container is unmounted Error: Failed to undump VE Resuming... vzquota : (erro........

OpenVZ/vzctl how to do an on-line migration without downtime

vzmigrate --online dest-host VEIDNO eg.: vzmigrate --oneline 192.168.1.55 101 One option I would recommend is "--keep-dst", that way if the migration is interrupted you can still bring the VPS back up on the original host. After the migration is successful you can manually destroy it. OpenVZ has a good writeup on this including Checkpointing and Restoring etc:........

OpenVZ iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. Solution

This error is annoying, in a Virtuozzo KB entry about this ip tables nat problem they say the kernel needs to be ugpraded: Symptoms The node runs 2.6.18-x kernel older than 2.6.18-028stab053.10. NAT module does not work in container, you get "can't initialize iptables table 'nat'" error: # iptables -t nat........

After installation Directadmin does not work directadmin dead but pid file exists on OpenVZ VPS when browsing http://ip.ip.ip.ip:2222

After installation Directadmin does not work on OpenVZ VPS when browsing http://ip.ip.ip.ip:2222 service directadmin status directadmin dead but pid file exists tail /var/log/directadmin/error.log Check the value of your ethernet_dev=eth0 setting in your /usr/local/directadmin/conf/directadmin.conf file and the output of /sbin/ifconfig 2010:07:10-12:44:01: ioctl can't find........

Openvz Enable Most Common iptables modules

The default options for iptables are very basic. Here is what you need to do in order to enable them in OpenVZ. 1.) Add the modules to iptables and restart iptables: vi /etc/sysconfig/iptables-config Edit the line as so: IPTABLES_MODULES="ipt_REJECT ipt_tos ipt_TOS ipt_LOG ip_conntrack ipt_limit ipt_multiport iptable_filter iptable_mangle ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_length ipt_state iptable_nat ip_nat_ftp" 2.........

Unixbench Score on Core i5 750 with OpenVZ Kernel vs Xen/Openvz

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........

OpenVZ user_beancounters kmemsize failcnt Processes Timing Out/Doing Nothing/Zombie

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........

CPanel OpenVZ VPS Error - * Notice * No working loopback device files found. Try running `modprobe loop` as root via ssh and running this script again.

Ihave no idea how to get the loopback device working in OpenVZ, but what's more frustrating is that I purchased a CPanel license for my VPS and clearly it is not "VPS Optimized". Although everything does seem to work at this point despite that error. The suggestions here: http://forum.openvz.org/index.php?t=msg&goto=1339 don't seem to work at all. This is an OpenVZ issue, but also a CPanel isue, why on earth would loopback support be expected in a VPS a........

Starting online migration of CT 300 to 192.168.5.45 Error: vzcpt module is not loaded on the source node Error: Can't continue online migration Error: vzcpt module is not loaded on the source node Error: Can't continue online migration

Starting online migration of CT 300 to 192.168.5.45 Error: vzcpt module is not loaded on the source node Error: Can't continue online migration Error: vzcpt module is not loaded on the source node Error: Can't continue online migration This is a very easy fix, you just load the appropriate modules on the source and target node (althoughI don't know why the vzmigrate tool can't do that for the user on both ends):........

OpenVZ backup container to a single file while it's running using "vzdump"

Proxmox has made this free utility to backup running OpenVZ containers. It's a great program which is actually just a PERL script but gets the job done. This program is not 100% required because all it really does is cp -a from your container's path as far as I know but it is still good to have uniformity to how you backup your containers. For RPM distros such as Centos/RHEL/Fedora etc.. download and install this: wget http://www.proxmox.com/cms_proxm........

heartbeat is stopped for some reason

heartbeat is stopped for some reason Anyway hnode2 was active and the services are running fine but I see heartbeat has been stopped somehow. Here is the last log I see of heartbeat: [quote:23c84415f5] Sep 9 17:15:32 hnode2 heartbeat: [16738]: info: MSG stats: 9/1762471 ms age 0 [pid16738/MST_CONTROL] Sep 9 17:15:32 hnode2 heartbeat: [16738]: info: cl_malloc stats: 716/51784021 152624/74519 [pid16738/MST_CONTROL] Sep 9 17:15:32........

Intel's Finnish Fetish

Intel's Finnish FetishIntel's Finnish Fetish By Dave Mock June 13, 2005 Chipmaker Intel (NASDAQ: INTC) has successfully topped the personal computer market for decades. Breaking into related areas such as communications has been much difficult for the world's largest semiconductor maker. But a new partnership with Nokia (NYSE: NOK) could help to change that. Intel's forays into cellular-phone and home-entertaiment-device chips have........

Openvz "Container already locked" Error Message Solution/Fix

I didn't find any useful information that actually fixed this. My VPS was in the "Running State" and I could not stop or restart it. I kept getting "Container already locked" no matter what Idid (I tried all the suggestions in the Google results for this error). Most of the suggestions were for Windows but I only use Linux. The other solutioins also said to restart the VZ service or even the entire hostnode and this was not acceptable to me........

Unixbench Score with Glusterfs/Openvz & Quad Core Xeon - Updated with GlusterFS 2.0.8 & Optimized Client Config

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........

Unixbench Score with Glusterfs/Openvz & Quad Core Xeon - Updated with GlusterFS 2.0.8

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........

Unixbench Score with Glusterfs/Openvz & Quad Core Xeon

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........

sudo: Error dropping capabilities, aborting in Linux Centos 5.3

For some reason Ikeep getting this error when trying to run a sudo command eg: sudo -u someuser somecommand sudo: Error dropping capabilities, aborting My version of sudo is:sudo-1.6.9p17-3.el5_3.1 and I've heard that version 1.7 fixes everything. The only thing is yum does not think sudo has any update. Iguess the new version has not been committed to the RPM repository yet. This is really a huge and ann........

Have an OpenVZ VPS/Linux Virtual Private Server and nothing works right?

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........

OpenVZ/Virtuozzo Enable Fuse in Container

To enable Fuse to work inside a OpenVZ container it's very simple (although some people say it can't be done). Remember that on your HN(HostNode) for OpenVZ, Fuse must be installed and the module must be loaded for this to work. In addition remember that you need the Fuse package installed inside the container of course. vzctl set 2000 --devices c:10:229:rw --save vzctl exec 2000 mknod /dev/fuse c 10 229 The part that most people forget........