1,734
edits
Changes
Leaflet
,added categories
= Container-based virtualization for Linux. Fast, lightweight, secure. Choose three. =
== What is OpenVZ? ==
OpenVZ is a project that combines the following container virtualization technologies for Linux:
*'''Virtuozzo kernel''' is , a Linux kernel with patches that implements OpenVZ kernel functionality. *'''Management utilities''', such as vzctl, to manage container life cycle. *'''Checkpoint/Restore In Userspace''', or CRIU (pronounced kree-oo, IPA: /krɪʊ/, Russian: криу), is a software tool for Linux operating system. Using this tool, you can freeze a running application (or part of it) and checkpoint it to a hard drive as a collection of files. You can then use the files to restore and run the application from the point it was frozen at. The distinctive feature of the CRIU project is that it is mainly implemented in user space. Docker and LXC uses CRIU to be able to migrate containers between servers.
*'''P.HaulManagement utilities''' is the project on top of CRIU that implements live migration usage scenario, such as vzctl, for managing container life cycle.
*'''LibCTCheckpoint/Restore In Userspace''' , or CRIU (pronounced kree-oo, IPA: /krɪʊ/, Russian: криу), is a container management library which provides convenient API software tool for frontend programs Linux that enables you to manage freeze a container during its whole lifetimerunning application (or a part of it) and checkpoint it to a hard drive as a collection of files. You can then use the files to restore and run the application from the point it was frozen at. The distinctive feature of the CRIU project is that it is mainly implemented in userspace. Docker and LXC use CRIU for migrating containers between servers.
'''2005''': SWsoft created the OpenVZ Project to release the core of Virtuozzo under GNU GPL.2005: SWsoft acquired a hosting/development company "Express" with their own containers for FreeBSD (it was later dropped due to small number of clients).
*Apr 2015: The source code of the RHEL7-based kernel is published and kernel development process becomes open.
*Jun 2015: The source code of most userspace utilities is published.
*Jul 2015: A yum repository with Virtuozzo RPM packages and installation ISO image is published and regularly updated.
*Jul 2015: Virtuozzo 7 Technical Preview - Containers is announced.
== Frequently Asked Questions ==
'''What is a container (Virtual Environment, Virtual Private Server)?'''
A container (CT) is an isolated entity which performs and executes works exactly like a stand-alone standalone server. Containers can be rebooted independently and have root access, users/groups, IP address(es)addresses, memory, processes, files, applications, system libraries , and configuration files.
'''What is a virtual machine?'''
'''What are the highlights of OpenVZ technology?'''
OpenVZ is a highly scalable virtualization technology for Linux with near-zero overhead, strong isolation and rapid customer provisioning that's is ready for production use right nowout of the box. Deployment of OpenVZ improves efficiency, flexibility , and quality of service in the enterprise environment.
'''How is OpenVZ different from other technologies?'''
Virtual Machines machines boot separate kernels on emulated hardware instances. OpenVZ runs all containers under a single Linux kernel. OpenVZ offers a much higher density, hosting enabling to host thousands of containers on a single physical server, but can only run Linux in those containers. Virtual machine solutions usually top out at a few dozen instances, but can run different operating systems in each.
'''What is the relationship between OpenVZ and LXC?'''
OpenVZ develops a new container technology that then goes upstream into the vanilla Linux kernel. OpenVZ has an about a 5 year headstart head start on LXC, but is actively feeding the technology upstream into vanilla containers. Several internal details currently differ (OpenVZ adds new system calls, vanilla uses the cgroups filesystem, new clone flags, and other mechanisms). '''What applications can run inside an OpenVZ container? ''' Applications and services do not have to be aware of OpenVZ, and most install are installed without any modifications: Java, Oracle, DB/2, Weblogic, Websphere , and many other big applications run just fine inside OpenVZ containers. However, direct access to hardware is not available by default; if required it must be provided by the system administrator.
'''How scalable is OpenVZ?'''
OpenVZ scales as well as Linuxdoes: we've tested 64 CPUs with 128 GB of RAM. It scales down to embedded devices like smart phones or plug computers. A single container can dynamically scale to take from taking a tiny fraction to all available resources, and may that can be adjusted without restarting itrestart.
'''How does OpenVZ improve efficiency?'''
OpenVZ improves utilization of existing hardware by increasing average load while still providing the ability to handle peak loads. When buying new servers, using a few powerful boxes instead of many little small ones allows better reliability, better peak performance and typically longer lifespan.
'''How does OpenVZ improve flexibility of services?'''
Each container is hardware -independent, and can be moved to another OpenVZ-based system over the network in seconds. This eases hardware maintenance (move out all containers and do whatever you need with the box) and improves availability (keep a synchronized copy of your container elsewhere and start it up if primary service fails). When your old box can no longer cope with peak load, you can live migrate your containers to a new one.
'''What is the performance overhead?'''
Near zero. There is no emulation layer, only security isolation and resource accounting. All checking is done in the kernel without context switching.
'''Where do I get (or put) more answers?'''
=== Server Consolidation ===
* Uniform management .* Easy to upgrade from Virtuozzo OpenVZ edition to the commercial Virtuozzo.* Scalable .* Fast migration .
=== Development and Testing ===
* Different distros can co-exist . * A container can be created in a minute.* Can A server can have hundreds of containers .* Cloning, snapshots, rollbacks are available. * A container is a sandbox: one can work/and play, no without fear .
=== Security ===
* Give each app its own isolated container .* Security hole in an app will not affect others .* Dynamic resource management controls runaway processes.
=== Hosting ===
* Isolated users Users are isolated. * A container is like a real server, just cheaper .* Much easier to admin administer.
=== Education ===
* Every student can have root access.* Different distributions are supported.* No need for a lot of Low hardwarerequirements.
Stay tuned: https://twitter.com/_openvz_
== See also ==
* [https://github.com/fedoradesign/flock2015booklet Fedora Flock 2015 booklet]
[[Category:Events]]
[[Category:Design]]