live migration change qcow2 disk into raw

[Gian-Piero Borello]

Hi,

First of all let me say thanks to the Proxmox Team for the wonderful work they are doing. I really like PVE.

Last week I have installed a couple of Proxmox 6.0 nodes to test them before migrating my 5.x production servers.

My nodes setup has only local storages (no shared storage) and I use qcow2 disk format for my vms

Trying to migrate node-to-node a stopped vm everything works fine (the process ends and the disk format are still qcow2), vice versa if I try a live migration (running vm) the process ends with no issues but the vm disks are converted to a raw format!

Is that behaviour a bug or a wanted feature or I do not understand how to use the live migration having qcow2 vms?

Can you help me?

Thanks

 

[tom]

Please file a bug on https://bugzilla.proxmox.com

 

[Gian-Piero Borello]

Hi, thanks for your fast reply.

Before following your hint, and open a new bug in bugzilla, I took a look to the Proxmox bugzilla system and I found a bug (https://bugzilla.proxmox.com/show_bug.cgi?id=2070) which is quite similar to mine. So I repeated the tests discovering that:

1) if you use the gui for live migrate node-to-node => The migration is OK BUT the vm disks format are always converted to raw

2) if you use the cli for live migration node-to-node using the following command:

qm migrate vm_number destination_node --with-local-disks --online => The migration is OK AND the vm disks are NOT converted to raw

3) if you use the cli for live migration node-to-node using the following command:

qm migrate vm_number destination_node --with-local-disks --online --targetstorage destination_storage => The migration is OK BUT the vm disks are converted to raw

So it seems that the Proxmox 6.0 migration gui always adds the --targetstorage parameter to the migration command and doing that the system chooses to convert the disks format from qcow2 to raw type.

So for now I think it's better not to use the live-migration gui and use the cli.

Best regards

Gian-Piero

 

[Sralityhe]

Hi Proxmox Team,

seems like this is still a thing.

Any Updates?

Thanks!

 

[larsen]

Experiencing the same problem. The bug report states that a patch has been applied on 2020-01-21.

When will a new version be released?

 

[tom]

Experiencing the same problem. The bug report states that a patch has been applied on 2020-01-21.

When will a new version be released?

Already available.

(since qemu-server: 6.1-5)

 

[larsen]

My server has 6.1-6 but still the disk got converted from qcow2 to raw when I live migrated via the GUI yesterday.

 

[tom]

My server has 6.1-6 but still the disk got converted from qcow2 to raw when I live migrated via the GUI yesterday.

works here. please check/compare your:

pveversion -v on both hosts.

 

[larsen]

Ah, found my mistake: The new host has been freshly installed, but apparently needed the "pve-no-subscription" repository added and upgraded to get the most recent version. Haven't tested but this should be fine then.