Top Reasons to pick OpenVZ over KVM

Quags

Administrator
Staff member
I had posted at http://www.interserver.net/forum/threads/top-reasons-to-pick-kvm-over-openvz.671/#post-933 the reasons you may want to pick KVM over openvz. Here are the reasons you would pick openvz over KVM

1) Faster DISK IO
- openvz Disk IO is faster because of a shared file system / near zero overhead / single kernel layout.

2) Automatic rebootless kernel upgrades. We use kslice on the hostnode, so kernel upgrades are automatically applied with out a reboot (zero downtime). Also a hostnode kernel upgrade applies to your own VM.

3) Choice of 32 or 64 bit VM's available. KVM only offers 64 bit VM's.

4) Price - Openvz plans start at $6 per slice while KVM starts at $10 per slice. However, KVM needs 2 slices to run due to the additional overhead.
 

codger

New Member
...

2) Automatic rebootless kernel upgrades. We use kslice on the hostnode, so kernel upgrades are automatically applied with out a reboot (zero downtime). Also a hostnode kernel upgrade applies to your own VM.
....

I admit I know little about openvz and should probably spend the time to do so. But I'm a bit confused by the last sentence of item 2), "Also a hostnode kernel upgrade applies to your own VM."

What does that mean, exactly in the Interserver environment?

Thanks!
 

Quags

Administrator
Staff member
Openvz is a single kernel across all VM's. So when we use Ksplice.com to upgrade a kernel it covers all VPS's on the system.

KVM you use your own kernel, if we ksplice the hostnode kernel your VPS does not update.
 

codger

New Member
Still a bit confused. I see an option for ksplice in the upgrades at $3.95/month - do I need to pay that to ensure kernel upgrades, or not?
 

Quags

Administrator
Staff member
You can just upgrade the kernel with a reboot if you want.

Ksplice just allows rebootless kernel update.
 

bauss

New Member
Why is OpentVZ cheaper? I got a OpenVZ with InterServer. I'm just curious why it costs less if it's better.
 

Quags

Administrator
Staff member
Because of the architecture of openvz, more containers can be fit on an system which is why it is cheaper. This is because there is one kernel server wide for the entire system - on kvm each has its own kernel and the over head is higher.
 
dont forget about any java apps on your server. java is not very happy on openVZ.

also, when i first became a interserver acolyte, Quags was patient enough with me to tell me that kvm is more easily upgraded to the cloud server while openVZ requires an upgrade, which is like starting over.

these reason alone should settle any question!
 

Omni

New Member
dont forget about any java apps on your server. java is not very happy on openVZ.

also, when i first became a interserver acolyte, Quags was patient enough with me to tell me that kvm is more easily upgraded to the cloud server while openVZ requires an upgrade, which is like starting over.

these reason alone should settle any question!
The "Java works better on KVM" is noted in the KVM thread.

OpenVZ offers faster performance and is cheaper. All the VPSses I've owned were all OpenVZ since I don't really see a reason to go with KVM. However I didn't know that Java works better on KVM than it does on OpenVZ so I might go with that in the future for the minecraft servers I occasionally set up for my friends. Thanks for the information.
 
but don't forget if you ever want to migrate to the cloud, kvm puts you into a much better position.

i started out life on the openVZ but switched over to KVM for a number of reasons. i am completely satisfied with the kvm service.
 
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Omni

New Member
but don't forget if you ever want to migrate to the cloud, kvm puts you into a much better position.

i started out life on the openVZ but switched over to KVM for a number of reasons. i am completely satisfied with the kvm service.
Which are the reasons why you took KVM over OpenVZ? I would like to know a few, because I don't know any of them except for the ones stated in the KVM thread.
 
i was having problems with the red5 server (java based) -- also, i wanted to position myself to migrate easily over to the cloud. those were my primary driving reasons. Quags mentioned some linux core upgrading that could be done with no down-time too.

i have been very happy with interserver KVM service. no complaints at all.
 
I see a lot of people like KVM much more than OpenVZ. Some of them, actually, seem to think that OVZ is BS!

I found out that some providers offer an excellent OVZ boxes with great stability and very good performance, when some KVM boxes are disappointing (terrible disk ios and cpu).

It's way better to pick KVM.
 

oGeraldJ880

New Member
my spouse 74-409 and i was having problems with the red5 server (java based) -- furthermore, i want to to put myself in order to migrate very easily up to the particular cloud. these have been our primary generating motives. Quags stated a few linux key changing that may be through with simply no down-time way too.

i have already been happy using interserver KVM services. simply no claims by any means.
 
T

ThaiReales

Guest
Hello to everybody, new in here.

Excuse when I squeeze in here, but I learnt that KVM is also offering more stability "because" it is more independent. I experienced an absolute nightmare with my previous host when they had to replace a DISC. My sites were down for over 3 days, and continue to fail - downtime was up to over 10% I'd say, ever since. If I would have run on a KVM (so I'd been told) I could have avoided this.

Anyone knows anything about that?
 
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