Openvz - a quick introduction
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OpenVZ is a virtualization software that allows multiple containers to share a single Linux kernel while providing features like live migration and quick backups. Containers are full Linux systems with separate user databases and network interfaces, and they can be managed using tools such as vzctl and vzlist. The document provides an introduction to the setup and configuration of OpenVZ, as well as advanced features and helpful references.
Openvz - a quick introduction
- 1. Introduction to OpenVZ [email protected] Olle E. [email protected] Johansson * [email protected] * Twitter oej © Copyright Edvina AB, Sollentuna, Sweden 2012. All rights reserved.
- 2. OpenVZ • Virtualization software by Parallells, inc. Base for their commercial Virtuozzo platform • Integrated with the virtualization support in the kernel - lvc • Segmentation, not full virtualization • Regardless, has cool features Introduction to OpenVZ
- 3. Cool features • Migration of running system • Backup with just a few secs stop time • Very simple - shared filesystem in the host system Introduction to OpenVZ
- 4. Basics Containers share the same kernel. Only Linux is supported - but you can run Kernel a different distribution in Container 1 a container. OpenVZ The host system Containers get allocated a few runs a full Linux with a Container 2 resources - network, CPU, standard kernel with memory, disk. openvz extensions. Introduction to OpenVZ
- 5. The container is a full Linux system • The container is a full Linux system • It has network interfaces (if configured) • It has a separate user account database (/etc/passwd) • It needs patching and updates like any other system Introduction to OpenVZ
- 6. The Kernel • The kernel is managed as an package for the distro you are using. • For Centos, you add a new yum repository and install the kernel • Reboot and you have OpenVZ support • Now install the tools - vzsplit, vzctl and vzlist Introduction to OpenVZ
- 7. vzctl • Used to manage containers • Create new container • Start container • Stop container • Change attributes (name, IP address, various limits, properties) Introduction to OpenVZ
- 8. vzlist • Simply list containers running in a system • Lists all container IDs Introduction to OpenVZ
- 9. vzsplit • Used to get settings for vzctl (or the .conf files) • Takes all resources in a server and divides them between a specific number of containers Introduction to OpenVZ
- 10. Beancounters • Counters that document use • Also document when a resource limit is exceeded • cat /proc/user_beancounters • Used to design system and manage issues • Watch the failcnt column! Introduction to OpenVZ
- 11. Networking • Ethernet interface via nat or bridge • The bridge interface enables DHCP and other broadcast /multicast technologies • IPv4 and IPv6 support • Firewall with IPtables in container or outside in host system (on the bridge) • Network traffic can be managed Introduction to OpenVZ
- 12. Script hooks • There are hooks for scripts you can run when starting and stopping containers • These can be used to mount disk drives into container Introduction to OpenVZ
- 13. Configuration • Configuration file in /etc/vz/vz.conf • Configuration for containers in /etc/vz/ conf Introduction to OpenVZ
- 14. Advanced features • Live migration of containers between systems • Backup of running system • Remote management with libvirt Introduction to OpenVZ
- 15. References • www.openvz.org • Documentation • Wiki full with information, howto’s and documentation • Downloadable templates for containers - Centos, Debian, Ubuntu and other distributions Introduction to OpenVZ