Better disk format and net (virtio or scsi)

[rmoglia]

I see for windows kvm aways choose IDE.

Im installing debian lenny guest 32 bits on proxmox
whats the best disk format. (virtio or scsi).

For compatibily issues like migrate between plataforms.
Have any restrictions?

Who is the best (virtio or scsi).

For networks virtio on debian guest is the best option?

 

[nextime]

I see for windows kvm aways choose IDE.

Im installing debian lenny guest 32 bits on proxmox
whats the best disk format. (virtio or scsi).

For compatibily issues like migrate between plataforms.
Have any restrictions?

Who is the best (virtio or scsi).

For networks virtio on debian guest is the best option?

After few days of tests, with disks images on raw files (DON'T USE QCOW!), the best way is to use virtio for both network and disks.

 

[valshare]

Hi,

why dont use qcow?

Regards, Valle

 

[nextime]

At least with debian guest 32 bit ( with both custom from vanilla and debian standard kernels ) it has problems used with virtio.

See:
http://www.proxmox.com/forum/showthread.php?t=1797

 

[mangoo]

After few days of tests, with disks images on raw files (DON'T USE QCOW!), the best way is to use virtio for both network and disks.

virtio network is currently broken in Proxmox - due to patches to kvm which add "fair scheduler" functionality, KVM guests will get "slow" after a couple of days (may depend on the number of guests running and the load they have).

So it's best to use e1000 network driver until it's fixed.


For block device, virtio driver works well.

 

[BiagioParuolo]

From 24th Sep new drivers are downlodable ( http://www.linux-kvm.org/page/WindowsGuestDrivers/Download_Drivers ).
Are them stable and compatible with ProxMox ( net and disk )?

 

[BiagioParuolo]

Is it possible to scsi disk type in win kvm machine?

 

[ion-ral]

for example, from my tests I found that if you currently use Windows 2008 is best to use ide drive as the net I have not tried, but if you use Debian Lenny (always 64bit) is much better virtio

 

[BiagioParuolo]

Uhm...some time ago, Windows kvm with scsi was not more compatible...then is still so. I thinked that with new version this problem was resolved...
So I use IDE...but will be slower then scsi...

 

[rmoglia]

At this moment im using only openvz not using kvm on prod enviroments.

 

[dietmar]

So I use IDE...but will be slower then scsi...

No, it will not be slower than scsi - why do you think so?

 

[BiagioParuolo]

Hi,

I think so, because guest s.o. see IDE disk instead SCSI disk...

 

[martin]

I think so, because guest s.o. see IDE disk instead SCSI disk...

Sure, but both are fully virtualized devices, so there will be no speed difference.

 

[rmoglia]

Sure, but both are fully virtualized devices, so there will be no speed difference.

Any diference if use IDE too?

 

[BiagioParuolo]

So, If there are not speed difference, Why are there?

 

[mangoo]

So, If there are not speed difference, Why are there?

Mainly for legacy systems (SCSI-only support, IDE-only support etc.).

 

[BiagioParuolo]

Do you suggest to use VIRTIO for drive in Win2008R2 with SQL Server on it or a solution with IDE on C: and Virtio for other drives ?

 

[andreas70]

Do you suggest to use VIRTIO for drive in Win2008R2 with SQL Server on it or a solution with IDE on C: and Virtio for other drives ?

I use use VIRTIO for all Disks + Network with Win2k8R2, fast and stable!