Choosing KVM vs OpenVZ

[mareksmareks]

Hello.

For reasons not to be mentioned we will need to move our shop to new server at the end of year.

Right now we have VPS with KVM virtualization.

We have found new host but can`t decide to choose OpenVZ or KVM.

Maybe we could get some good arguments here?

 

Right now we have these stats.

- daily visits: ~400-500

- ram: 1.18 GB used, 1.96 GB total

- storage: 26.37 GB used, 43.28 GB total (and growing every day as we add new products. Right now we have 5000 roducts, but can max up to 15`000 easy)

- processor: QEMU Virtual CPU version 1.5.3, 2 cores (probably not so important)

- daily backups to Amazon servers

 

So we have to choose between these two options:

CPU: 2 x 2.40 GHz

RAM: 4096 MB

SSD: 80 GB (800 IOPS)

Bandwidth: 20 TB

Port speed: 200 Mbps

Backups: Optional

Virtualization: KVM

 

and 

 

CPU: 3 x 2.40 GHz

RAM: 4096 MB

HDD: 160 GB (300 IOPS)

Bandwidth: 8 TB

Port speed: 300 Mbps

Backups: Daily, Weekly

Virtualization: OpenVZ

Price is definatley better for OpenVZ.

 

Right now on current server I don`t see much gain or effect from KVM. So i have my doubts for keeping KVM. 

On one hand new hosts KVM offers SSD, on the other hand OpenVZ gives more GB and faster port speed and bit better cpu. Bandwith would`nt be a problem at any of these options.

 

So what do you guys think?

 

[mareksmareks]

Nobody?

[selectshop.at]

I will prefer KVM.

OpenVZ is not a "real" virtualization solution where a whole server is virtualized. OpenVZ is also known as the Linux container. The virtual server uses large portions of the Linux host operating system - including its kernel - to provide "virtual servers" for the individual users but shielded environments. This is also a limitation: OpenVZ is only able to virtualize Linux operating systems and you have no possibility to make changes to the kernel of the guest system (since this is the host system). Access to the hardware is done directly - without a virtualization layer. This applies in particular to the working memory. All guests share the RAM of the host system - but this is not reserved when the virtual guest servers are started. So here on a server with 32 GB Ram 50 hosts with 1 GB RAM each can be operated. As long as the RAM is not claimed, everything is fine - but if all the guest systems simultaneously use the available RAM, this is quite good for the performance. The host (and thus also the vServer) begin to swap. This naturally influences the performance of the guests.

Another possibility is XEN. which is near to KVM

Xen is a "real" virtualization solution. Here, complete virtual servers are provided, in which almost every guest operating system can be installed. Xen is seen as a kind of its own operating system (it is a BareMetal hypervisor), whose task is to provide and manage virtual environments. Xen virtualization can be subdivided into PV (paravirtualization) and HVM (hardware virtual machine) - which each have some special features.

 

KVM is the latest representative of the three mentioned virtualization solutions. The approach most closely resembles that of XEN, although this is not a separate operating system. KVM is available as a kernel module for the Linux kernel. Thus the hypervisor - the virtualization software - runs also very close to the hardware, if not as close as with Xen. The use of a suitable hardware with virtualization functions (Intel VT or AMD HyperV) is also indispensable for operation. Complete virtual servers (with their own virtual hardware) are installed in which almost every guest operating system can be installed. Here too, device drivers exist that allow direct use of the host hardware without an abstraction layer.

Completely packaged KVM kernel modules exist for many Linux distributions. Installation of your own KVM host should be relatively simple.

 

 

[mareksmareks]

Thank you for copy-paste about technical stuff - I know all that. At least you could skip XEN part because it`s not relevant.

Of course if you should answer what is better in general then KVM is always better. But there are considerations to keep in mind that i mentioned (and selectshop.at clearly did`nt read that).  

Im kind of annoyed by these kind of answers - i got an answer but it helped me nothing.

[selectshop.at]

Well, what to say to that... Come one - copy/paste, very poor statement. If you don't expect answers, why are you posting here ?

I described you the diff. techniques, perhaps not clear for you till now. Furthermore I don't know your know-how level and presumed that you are not experienced. On top of that you have other places for to get experienced values. Prestashop forum is for to Prestashop problems, but not really for to clear such questions. This is also the reason why nobody answered you. Users here do not even know the difference between shared host, dedicated host and VPS. And I wasted my time for to answer you....

Not long ago I was using openvz, now I'm on KVM and there are several plus points for this system. Most of companies (bigger size) uses Windows Networks and only with KVM you will have an  interface, but not with openvz. That was the reason why I changed to KVM. What you exactly need, you have to decide by yourself, we don't know what you want to do or want to fulfill. Other and relevant forums should give you better help for you question/decision.

 

 

[mareksmareks]

So you changed to KVM only because bigger companies use it?

As I said, im now on KVM and I don`t feel this server any different as my other openvz servers. But this KVM is my main server for business

[selectshop.at]

My needs are: also Windows as virtualized operating system. This is not possible on openvz. The way thru virtualbox was not satisfactory  enough. It is a hack, but not a real solution. Therefore KVM.