Beginners questions to backup/restore with Proxmox VE

[fbn]

Hi,

we are administrating some dedicated servers with webserver, mailserver, database etc. We backup all files every night but we have no system backup, that means to restore a server we have to install the OS and servers manually and then restore the data afterwards.

To improve this process we are thinking about using Proxmox VE on our dedicated servers. One hardware will only run one productive virtual server and maybe a clone of the virtual server. This virtual server will be saved every night, the backup will be stored on a FTP server.

According to the Proxmox wiki OpenVZ would be the better choice for this environment as it enables better server utilization. So far we only know full virtualization (KVM / VMware / XEN) and have no experience with OpenVZ. Therefore we have some questions:

1. Is there much performance difference between OpenVZ and KVM if we only run one productive virtual server on the hardware?

2. Can we backup and restore OpenVZ virtual servers like it's possible with KVM virtual servers?

3. Can we migrate virtual servers from one hardware running Proxmox to another hardware running Proxmox? Even if the underlying hardware and OS (Linux) changes?

Thanks in advance,
Frank

 

[tom]

Hi,

we are administrating some dedicated servers with webserver, mailserver, database etc. We backup all files every night but we have no system backup, that means to restore a server we have to install the OS and servers manually and then restore the data afterwards.

To improve this process we are thinking about using Proxmox VE on our dedicated servers. One hardware will only run one productive virtual server and maybe a clone of the virtual server. This virtual server will be saved every night, the backup will be stored on a FTP server.

According to the Proxmox wiki OpenVZ would be the better choice for this environment as it enables better server utilization. So far we only know full virtualization (KVM / VMware / XEN) and have no experience with OpenVZ. Therefore we have some questions:

1. Is there much performance difference between OpenVZ and KVM if we only run one productive virtual server on the hardware?

depends on your usage scenario, what application do you run. but generally speaking, OpenVZ is the way to go. But you can only run Linux as OpenVZ.

2. Can we backup and restore OpenVZ virtual servers like it's possible with KVM virtual servers?

yes, see vzdump. as containers are smaller, all these operations are faster.

3. Can we migrate virtual servers from one hardware running Proxmox to another hardware running Proxmox? Even if the underlying hardware and OS (Linux) changes?

Thanks in advance,
Frank

OpenVZ works with local storage. If you use the default 2.6.18 kernel branch you can live migrate without any downtime - quite cool as it works out of the box and you do not need any SAN or and other complicated setup. if you decide to leave Proxmox VE, you can still restore/migrate these container to any other Linux with OpenVZ Kernel.

 

[udo]

Hi,

we are administrating some dedicated servers with webserver, mailserver, database etc. We backup all files every night but we have no system backup, that means to restore a server we have to install the OS and servers manually and then restore the data afterwards.

To improve this process we are thinking about using Proxmox VE on our dedicated servers. One hardware will only run one productive virtual server and maybe a clone of the virtual server.

I think it's better to put the clone on a different server

This virtual server will be saved every night, the backup will be stored on a FTP server.

According to the Proxmox wiki OpenVZ would be the better choice for this environment as it enables better server utilization. So far we only know full virtualization (KVM / VMware / XEN) and have no experience with OpenVZ. Therefore we have some questions:

1. Is there much performance difference between OpenVZ and KVM if we only run one productive virtual server on the hardware?

Yes, but it's depends on your application (IO need more cpu on kvm).

2. Can we backup and restore OpenVZ virtual servers like it's possible with KVM virtual servers?

yes - the backup from pve works well.

3. Can we migrate virtual servers from one hardware running Proxmox to another hardware running Proxmox? Even if the underlying hardware and OS (Linux) changes?

Other hardware should not be an problem (you should have the same networkconfig - vmbr0,1...). Other OS? Perhaps this makes differences, because you use the same kernel in the VM. But why you don't want to use the same kernel?

Udo

 

[fbn]

Hi Tom and Udo,

thanks for your answers those are helpful.

@Udo: About different kernels: What if one installs a virtual machine (OpenVZ) in 2010 on kernel 2.6.34 and wants to migrate to a new hardware server in 2013 running kernel 2.6.46? I guess this would be no issue with KVM but what about OpenVZ?

 

[udo]

Hi Tom and Udo,

thanks for your answers those are helpful.

@Udo: About different kernels: What if one installs a virtual machine (OpenVZ) in 2010 on kernel 2.6.34 and wants to migrate to a new hardware server in 2013 running kernel 2.6.46? I guess this would be no issue with KVM but what about OpenVZ?

Hi Frank,
OpenVZ use the kernel of the host - at this time you can choose on proxmox between 2.6.18 and 2.6.24 (2.6.32 only kvm - openvz support perhaps later). With kvm you have the choice to use the kernel inside the VM you like but you pay with performance (for many things it will be no problem). I can't say what happens at 2013... but perhaps then is the right time to make a fresh install of the VM ;-)
OpenVZ-VMs are smaller and boots very fast (round about 2 second). I think you must try OpenVZ itself.
If your VM depends not on kernel-modules it should not be an problem to switch on a newer kernel later. E.g. a mysql-server run's well with 2.6.18, 2.6.24 ...


Udo

 

[fbn]

Hi Udo,

thanks for the explanation.

Frank