There have been a lot of technical advancements in virtualization technologies in the past years. However, the two most common virtualization technologies used by VPS hosting companies are Xen & OpenVZ (open-source version of Virtuozzo). There are a lot of differenes between the two technologies. In this article, we’ll demonstrate the main differences and the faster/better technology.
Xen is one of the most advanced virtualization technologies at the moment, Xen VPS hosting companies use this virtualization technology, most of the time alongside HyperVM to provide Xen based virtual private servers.
The advantage of Xen is it’s full isolation, compared to other technologies such as OpenVZ, where they simply “lock” the user. The advantages of those is the ability to compile your own kernels or load your own modules. Xen VPS hosting service level tends to be much higher than any other ones because of their inability to cram servers into a node, because when Xen runs, it allocates the RAM to itself so it cannot be shared. It also gives you your own swap, therefore, Xen VPS hosting gives you the same exact environment as a web hosting company.
This virtualization method is much less performing but it also provides a good return on investment for web hosting companies. OpenVZ allows hosts to put as much servers as they want without allocations.
There are no advantages with this technology except burstable RAM, which is rarely accessible because of how companies that provide OpenVZ VPS servers tend to cram them with as much servers as they can because they are not limited by allocations that are done by the hypervisor. It is also not a true virtualization environment, could even go to call it a jailshell, you cannot compile your own kernel neither any kernel modules. Also, cPanel tends to have problems with quotas and running under OpenVZ.