This page contains some longer HowTos for achieving different tasks on CentOS systems. Content in the 'HowTos' hierarchy is written because its author believes it to work (one assumes) and to provide value as a reference. All content ages as time passes, of course, and if a given article seems wrong, it may be updated or it simply may be abandoned. Sometimes when a page is stale beyond obvious repair, it will be marked as such after public reports of problems.
Dec 26, 2018 ALSO check that quota is disabled in Linux and OpenVZ has its own Quota management system and it will conflict if the OS’s quota is enabled. Root> quotaoff -vaug Cannot SSH to VPS. GIT – multiple Virtual Private Servers (VPS) by the use of OpenVZ on the same hardware, similar to Xen and the Linux Vserver projectThe OpenVZ kernel patch is licensed under the GPL license, and the user-level tools are under the QPL license. 1 Installing OpenVZ. To Install of OpenVZ wwant to add OpenVZ repository to yum.
The 'centos-docs' mailing list is a great place to point out possible errors or even better, offer improvements.
Contents
1. Backups
- BackupPC
- Rotational backup with remote backup options
- Backing up with Amanda
- Backups with rsnapshot
2. Directory Services
- Setting up CentOS Directory Server
3. Diskless Clients
- Diskless Clients using NFS and PXE
- Diskless Clients using K12LTSP
4. E-Mail
- vpopmail
- Postfix: A simple Postfix/Dovecot mail server
- Postfix Restrictions: Simple spam filtering with Postfix
- Postgrey: Spam filtering with Postgrey greylisting on Postfix
- Postfix SASL & SSL/TLS: SASL and SSL/TLS for postfix and dovecot
- Postfix SASL Relayhost: SASL for a relayhost
- Amavisd: Amavisd with ClamAV and SpamAssassin
5. Encryption
- Encrypting /tmp /swap & /home
- Encrypting your Filesystem
6. FTP
- Chroot Vsftpd with non-system users
- Simple SFTP setup without chroot
7. Webserver
- Setting up an SSL secured Webserver with CentOS
- Setting up kerberos authentication for apache httpd on CentOS
8. Kernel
- I Need the Kernel Source
- I Need to Build a Custom Kernel
- Build Your Own Kernel Modules
9. Network
- Setting up iptables on CentOS
- Configuring a High-Availability cluster with Heartbeat/DRBD
- Making Wireless work on your laptop (or desktop)
- Enabling NetworkManager
- Enabling wpa_supplicant without NetworkManager
10. Security
- Hardening CentOS
- SELinux Guide
- Securing SSH on your system
- Setting up iptables on CentOS
- Using vpnc on CentOS 5.x
![Install openvz on centos 7 documentation software Install openvz on centos 7 documentation software](/uploads/1/2/5/7/125788531/847783141.jpg)
11. Remote X Sessions
- FreeNX
- VNC
- Spice with LibVirt for VMs (CentOS-6.2 or Higher)
12. Migration
- Migration Guides
- ServerCD 4.4 migration to CentOS 5
- CentOS End of Life options
13. Package Management
- Yum
- RPM
- PackageManagement
- Fastest Mirror: yum plugin to determine and use the fastest CentOS mirror
- Priorities: yum plugin that allows ranking repository priorities from 1 to 99 ... can not be used with protectbase, but it has that functionality built in.
- Protect Base: yum plugin that prevents external repositories from overwriting CentOS packages
- YumCheckOrInstallUpdates: Shell script to automatically check for or install new updates.
- Install from Source: How (not) to install Software from Source on CentOS
- Rebuild a Source RPM (SRPM) package: How to rebuild a Source RPM package on CentOS
- Yum on RHEL: Using CentOS Repositories on RHEL machines
- Create a local mirror for updates or installs
- Create local repositories for your own packages
- CentOS Repositories
- Spacewalk
- Setting up a network install server
14. Virtualization
- Introduction
- Quickstart for Xen4 on CentOS-6
- Move a native CentOS4 installation into a Xen DomU
- Installing and using a CentOS 5 Xen domU instance
- Installing and using a fully-virtualized Xen guest
- Installing and using KVM on CentOS
- Using Nvidia drivers and Xen at the same time
- Vserver on CentOS
- OpenVZ on CentOS
- VirtualBox on CentOS
- CentOS as a Guest OS in VirtualBox
- Spice with LibVirt for VMs (CentOS-6.2 or Higher)
- Nested Virtualisation on CentOS-6
- Linux Container (aka LXC) Virtualisation on CentOS-6
- oVirt on CentOS
15. PXE
- PXE on CentOS
16. Storage devices, Logical Volume Management, and RAID
- How to Setup a Software RAID on CentOS 5
- How to install CentOS on partitionable software RAID volumes
- How to convert a CentOS 5 system to RAID1 using a rescue disk
- Disk/filesystem optimization
17. Misc
- Subversion on CentOS
- Java on CentOS 4 and CentOS 5
- How to install the Java Runtime Environment (JRE) from Java.com and configure plugins
- Configure a New Video Card
- Set Up a USB Key to Install CentOS
- Grub Installation for CentOS 5 and 6
- Install the FOG computer imaging solution on CentOS
- Setting up grub2 on CentOS 7
- Using PHP 7.x on CentOS 7.4
18. Non CentOS Applications
- Nagios on CentOS
- RT 3.4.x On CentOS 4.x
- Cacti on CentOS 4.x
- OCS Inventory NG on CentOS 5.x
- Skype on CentOS
- Oracle Database 12c Installation on CentOS 7
- GlusterFS Storage Cluster on CentOS 7
19. CentOS on Laptops
- CentOS on Laptops
20. CentOS on Intel-based Apple computers
- CentOS on iMac / Mactel
21. CentOS Guidelines
Some normative documents about CentOS:
- How to edit the CentOS Wiki
- How to contribute your RPMs to the CentOS Project
- Working with the CentOS Community Buildsystem
- How to create public mirrors for CentOS
On this page
- Installing And Using OpenVZ On CentOS 5.7
Installing And Using OpenVZ On CentOS 5.7
Version 1.0
Author: Falko Timme
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Author: Falko Timme
Follow me on Twitter
In this HowTo I will describe how to prepare a CentOS 5.7 server for OpenVZ. With OpenVZ you can create multiple Virtual Private Servers (VPS) on the same hardware, similar to Xen and the Linux Vserver project. OpenVZ is the open-source branch of Virtuozzo, a commercial virtualization solution used by many providers that offer virtual servers. The OpenVZ kernel patch is licensed under the GPL license, and the user-level tools are under the QPL license.
This howto is meant as a practical guide; it does not cover the theoretical backgrounds. They are treated in a lot of other documents in the web.
This document comes without warranty of any kind! I want to say that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take. I do not issue any guarantee that this will work for you!
1 Installing OpenVZ
In order to install OpenVZ, we need to add the OpenVZ repository to yum:
cd /etc/yum.repos.d
wget http://download.openvz.org/openvz.repo
rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ
wget http://download.openvz.org/openvz.repo
rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ
Now open openvz.repo...
... and disable the [openvz-kernel-rhel6] repository (enabled=0) and enable the [openvz-kernel-rhel5] repository instead (enabled=1):
The repository contains a few different OpenVZ kernels (you can find more details about them here: http://wiki.openvz.org/Kernel_flavors). The command
shows you the available kernels:
[[email protected] yum.repos.d]# yum search vzkernel
...
ovzkernel.i686 : Virtuozzo Linux kernel (the core of the Linux operating system)
ovzkernel.x86_64 : Virtuozzo Linux kernel (the core of the Linux operating system)
ovzkernel-PAE.i686 : The Linux kernel compiled for PAE capable machines.
ovzkernel-PAE-devel.i686 : Development package for building kernel modules to match the PAE kernel.
ovzkernel-devel.i686 : Development package for building kernel modules to match the kernel.
ovzkernel-devel.x86_64 : Development package for building kernel modules to match the kernel.
ovzkernel-ent.i686 : The Linux kernel compiled for huge mem capable machines.
ovzkernel-ent-devel.i686 : Development package for building kernel modules to match the ent kernel.
ovzkernel-xen.i686 : The Linux kernel compiled for Xen VM operations
ovzkernel-xen.x86_64 : The Linux kernel compiled for Xen VM operations
ovzkernel-xen-devel.i686 : Development package for building kernel modules to match the kernel.
ovzkernel-xen-devel.x86_64 : Development package for building kernel modules to match the kernel.
[[email protected] yum.repos.d]#
...
ovzkernel.i686 : Virtuozzo Linux kernel (the core of the Linux operating system)
ovzkernel.x86_64 : Virtuozzo Linux kernel (the core of the Linux operating system)
ovzkernel-PAE.i686 : The Linux kernel compiled for PAE capable machines.
ovzkernel-PAE-devel.i686 : Development package for building kernel modules to match the PAE kernel.
ovzkernel-devel.i686 : Development package for building kernel modules to match the kernel.
ovzkernel-devel.x86_64 : Development package for building kernel modules to match the kernel.
ovzkernel-ent.i686 : The Linux kernel compiled for huge mem capable machines.
ovzkernel-ent-devel.i686 : Development package for building kernel modules to match the ent kernel.
ovzkernel-xen.i686 : The Linux kernel compiled for Xen VM operations
ovzkernel-xen.x86_64 : The Linux kernel compiled for Xen VM operations
ovzkernel-xen-devel.i686 : Development package for building kernel modules to match the kernel.
ovzkernel-xen-devel.x86_64 : Development package for building kernel modules to match the kernel.
[[email protected] yum.repos.d]#
Pick one of them and install it as follows:
If the last command gives you errors like...
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol strcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol add_memory
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol swiotlb
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol memory_add_physaddr_to_nid
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol remove_memory
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol strcmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol acpi_get_node
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_unregister_ecc_decoder
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_register_ecc_decoder
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_report_gart_errors
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_decode_nb_mce
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/cpufreq/freq_table.ko needs unknown symbol strcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/cpufreq/freq_table.ko needs unknown symbol _cpu_pda
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/i7core_edac.ko needs unknown symbol edac_mce_register
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/i7core_edac.ko needs unknown symbol edac_mce_unregister
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/i7core_edac.ko needs unknown symbol __memcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol dma_ops
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol copy_from_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol bad_dma_address
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol find_first_bit
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol strcat
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol mem_section
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol copy_to_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol strncpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol __memcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol strcmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol alloc_pages_current
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/kernel/microcode.ko needs unknown symbol copy_from_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol cpu_to_node
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol copy_from_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol copy_user_generic
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol profile_pc
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol copy_to_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol strcmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/kernel/cpufreq/powernow-k8.ko needs unknown symbol strncmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/kernel/cpufreq/powernow-k8.ko needs unknown symbol _cpu_pda
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/pci/hotplug/shpchp.ko needs unknown symbol strcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol add_memory
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol swiotlb
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol memory_add_physaddr_to_nid
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol remove_memory
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol strcmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/acpi/acpi_memhotplug.ko needs unknown symbol acpi_get_node
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_unregister_ecc_decoder
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_register_ecc_decoder
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_report_gart_errors
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/amd64_edac_mod.ko needs unknown symbol amd_decode_nb_mce
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/cpufreq/freq_table.ko needs unknown symbol strcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/cpufreq/freq_table.ko needs unknown symbol _cpu_pda
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/i7core_edac.ko needs unknown symbol edac_mce_register
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/i7core_edac.ko needs unknown symbol edac_mce_unregister
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/edac/i7core_edac.ko needs unknown symbol __memcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol dma_ops
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol copy_from_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol bad_dma_address
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol find_first_bit
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol strcat
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol mem_section
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol copy_to_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol strncpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol __memcpy
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol strcmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/infiniband/hw/ipath/ib_ipath.ko needs unknown symbol alloc_pages_current
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/kernel/microcode.ko needs unknown symbol copy_from_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol cpu_to_node
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol copy_from_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol copy_user_generic
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol profile_pc
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol copy_to_user
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/oprofile/oprofile.ko needs unknown symbol strcmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/kernel/cpufreq/powernow-k8.ko needs unknown symbol strncmp
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/arch/x86_64/kernel/cpufreq/powernow-k8.ko needs unknown symbol _cpu_pda
WARNING: /lib/modules/2.6.18-274.el5.028stab093.2/kernel/drivers/pci/hotplug/shpchp.ko needs unknown symbol strcpy
... please remove ovzkernel...
... and install the ovzkernel package for your architecture:
On x86_64 systems:
On i686 systems:
This should automatically update the GRUB bootloader as well. Anyway, we should open /boot/grub/menu.lst; the first kernel stanza should now contain the new OpenVZ kernel. Make sure that the value of default is 0 so that the first kernel (the OpenVZ kernel) is booted automatically instead of the default CentOS kernel.
Now we install some OpenVZ user tools:
Open /etc/sysctl.conf and make sure that you have the following settings in it:
If you need to modify /etc/sysctl.conf, run
afterwards.
The following step is important if the IP addresses of your virtual machines are from a different subnet than the host system's IP address. If you don't do this, networking will not work in the virtual machines!
Open /etc/vz/vz.conf and set NEIGHBOUR_DEVS to all:
SELinux needs to be disabled if you want to use OpenVZ. Open /etc/sysconfig/selinux and set the value of SELINUX to disabled:
Finally, reboot the system:
If your system reboots without problems, then everything is fine!
Run
and your new OpenVZ kernel should show up:
[[email protected] ~]# uname -r
2.6.18-274.el5.028stab093.2
[[email protected] ~]#
2.6.18-274.el5.028stab093.2
[[email protected] ~]#