OpenVZ vs KVM vs XEN

I like XEN because the memory and some other resources are dedicated instead of shared. Plus it supports Windows operating systems. OpenVZ is good and easy to use but it's limited to Linux.

I like KVM as give you option for self mount iso

We utilize openvz,xen & kvm

its a end user customer preference really.

As a web host tbh its not really a personal preference for which one we want to offer.

I prefer KVM. Why? Because it's a full virtualization and you don't run into issues such as the user beancounters with OpenVZ, plus it's closer to the hardware than XEN.

^ The UBC is no longer an issue with vSwap introduced in RHEL6. KVM may be isolated, but it also means an additional overhead as opposed to OpenVZ which has the benefit of sharing certain resources/eliminating overheads.

OpenVZ is not as bad as people make it out to be; yes it can be abused and oversold. But if not abused/oversold, it will always outperform KVM/Xen.

And to add what Lifetalk said, ITs not abused & over sold if the host actually monitors his nodes

I have scripts setup to monitor mine & staff moniters them too

vSwap is compatible on CentOS 6+ systems and it works pretty great actually.

vSwap.

As a webmaster, I definitely prefer XEN over anything for the dedicated resources that I am assured of.

People generally tend to think that if a Webhost is selling OpenVZ VPS, they are going to be oversold. Which I can tell you, is not that easy a case as it seems. At least not in our case. We have a node for OpenVZ VPS which has about 16GB DDR3 RAM on it. So if it were to be dedicated to resources(like in case of XEN), it could fit in at most 31 VPS of 512MB RAM each.

But then we all know that all 31 VPS aren't going to run in full operation simultaneously at all times. This is where OpenVZ does provide greater flexibility. You could easily fit in another 10-15 VPS and still make sure that your node isn't going to blow up.

I use openvz... simple easy... :thumbup:

jure12 said:

I read all comments and I concluded that the "OpenVZ" very flexible and easy. The only defect is that "OpenVZ" can be oversold and therefore can have a very bad VPS if you bought from web hosting company that it works.

Xen is isolated but exactly which isolation hardware has? KVM is better isolated than Xen?

Click to expand...

Xen can also be oversold just for everyone, this is called ballooning but to be honest, I don't think many would waste the time to do it.

Everything can be oversold, it does not matter, what does matter is how the host manages the nodes and ensures abuse is dealt with.

OpenVZ can be bad mainly down to other users on the node abusing the CPU and Network, IO etc, Xen is great but can be effected by other users in regards to IO and network.

It depends what you want really, they both have good points and bad, they both can be oversold.

Xen is known to be more solid due to it giving dedicated resources to containers which are isolated from others where as OpenVZ containers are not really isolated, I have seen other users cause people's virtual servers to go slow but there is ways to maintain it by keeping some spare CPU space and limiting servers to an amount of CPU and number of cores.

jure12 said:

I read all comments and I concluded that the "OpenVZ" very flexible and easy. The only defect is that "OpenVZ" can be oversold and therefore can have a very bad VPS if you bought from web hosting company that it works.

Xen is isolated but exactly which isolation hardware has? KVM is better isolated than Xen?

Click to expand...

Anything can be oversold. Even that doesn't mean anything. A high end server that is oversold might still be better than you using a low spec server that isn't oversold. It doesn't mean much. What means a lot is the end result for the customer - how it appears to perform for them.

XEN-HVM would be the equivalent to KVM in terms of isolation. It is full virtualization. XEN-PV is only paravirtualization.