/ - rtt - IT Resource

  • 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........
  • How to qemu-kvm enable bridged networking in Debian Ubuntu Linux Mint on KVM containers


    I've read a few guides about this but they didn't work for me. sudo apt-get install bridge-utils #don't think the above is enough it won't work still even though you have by default an /etc/qemu-ifup that handles it if you have the right tools and setup sudo qemu-system-x86_64 -net tap -net nic -enable-kvm -cpu host,vmx=on ~/VirtualBox VMs/vsphere-vcenter/vsphere-vcenter.vdi W: /etc/qemu-ifup: no bridge for guest interface foun........
  • VirtualBox Nested Virtual Machine Containers with KVM Not Working no SVM or VMX module in the guest


    I can't get vmx cpu extensions to show up in Virtualbox guests despite enabling nested paging and enable vmx in virtualbox guest but this doesn't help that you check VT-X or the AMD Virtualization SVM it enables it for the guest to use BUT does not pass it through.  This means if you check cat /proc/cpuinfo in the guest you will see the CPU doesn't support virtualization.  It looks like VirtualBox still hasn't implemented this! But there is good news I&n........
  • 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........
  • 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........
  • 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.........
  • 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 I am 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     ........
  • 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.........
  • SolusVM error error: Failed to create domain from /home/kvm/kvm101/kvm101.xml error: cannot open file '/dev//dev/kvmcontainer/kvm101_img': No such file or directory


    error: Failed to create domain from /home/kvm/kvm101/kvm101.xml error: cannot open file '/dev//dev/kvmcontainer/kvm101_img': No such file or directory This is caused by what we consider a quark in SolusVM that I helped a client with. SolusVM has as config for the "LVM volume name" and does not enforce any convention. Naturally most technical people would use the actual path eg "/dev/kvmcontainer". However th........
  • 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...  ........
  • 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........
  • 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........
  • Xen non-HVM container won't work/boot anymore


    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........
  • 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........
  • 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.  I added another different IP on 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........
  • Kernel/make compilation time and how to improve compile times/compile the Linux kernel faster without hardware upgrades


    I thought only a faster CPU and SSD would 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........
  • Virtualbox How To Clone VM/Container VDI file


    You can't just do a straight copy of the VDI image of your virtual machine because there is a unique UUID, well I believe you can and then you can create a new UUID manually (at least you could with VMWARE) but to keep it clean just use this method: VBoxManage clonevdi /path/to/your.vdi outputname.vdi 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% That's all there is to it, just wait for it copy and you can th........
  • 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:........
  • 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........
  • Firefox plugin-container high CPU usage


    This is an easy fix and highlights a huge issue again with Linux and Flash still not playing nicely/working as well as Windows yet. Solution - Go to "about:config" and disable the two entries (set them to false):   dom.ipc.plugins.enabled.libflashplayer.so dom.ipc.plugins.enabled.libnptest.so........
  • VirtualBox Error Failed to start the virtual machine Centos 5.5 Mirror. Medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' is not accessible. UUID {a1a9fad7-0402-4867-b8f3-39fb49454bc5} of the medium '/home/testuser/.VirtualBox/HardD


    Virtualbox Error I tried to copy a .vdi of one container to use in another one, basically to clone instead of having to install the OS again. Failed to start the virtual machine Centos 5.5 Mirror. Medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' is not accessible. UUID {a1a9fad7-0402-4867-b8f3-39fb49454bc5} of the medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' does not match the value {4945a0e8-0ed5-4736-9088-bcaf........
  • 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 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 ........
  • Realtek r8169 1gbit/1000mbit NIC/Ethernet Goes Down/Halts on Large File Transfer/Heavy Network Usage


    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........
  • 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 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........
  • 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 I did (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........
  • sudo: Error dropping capabilities, aborting in Linux Centos 5.3


    For some reason I keep 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.  I guess the new version has not been committed to the RPM repository yet. This is really a huge and ann........
  • 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........
  • OCFS2 crash


    When trying to even cd or ls the mounted OCFS2 partition it crashes.  I think 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........
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