Virtuozzo
Virtuozzo (pronounced “Virtuoso”) is proprietary software for virtualizing operating systems and is developed and sold by Parallels, Inc. (prior to 2008 SWsoft, Inc.). The Linux version has been available since 2001, the version for Microsoft Windows has been available since 2005. The Linux version of Virtuozzo is based on OpenVZ .
description
Virtuozzo creates multiple, isolated virtual instances of an operating system on a single physical server . This offers the possibility of using existing hardware for several (virtual) servers.
Most of the time, the virtual servers behave as if they were individual physical servers. All instances have their own computer management (administration of groups and users, services, hard disk management), their own IP address (es), processes, data, applications , system libraries and administration files. Each virtual instance has its own network area and can therefore be reached via the network . Each instance can have its own routing tables and firewall rules, but due to the shared kernel it cannot load its own kernel modules (e.g. for extended firewall functionality).
Operating system virtualization
Virtuozzo does not virtualize on a hardware basis - as other software often does - but on the operating system basis. All instances run on a single kernel . Virtuozzo's virtualization mechanism “multiplies” this kernel so that the instances appear to run as their own operating system, especially from the point of view of applications, users and network services. As a result, the software generates less system load than other virtualization software. This means that more virtual instances can run simultaneously on a physical server than usual. Virtuozzo supports up to 64 x86 processors , but usually 1 to 4 processor machines are much more common in practice.