[pve-devel] Disk cloning feature for shared lvm storage

[Stefan Priebe - Profihost AG]

Am 14.10.2011 10:11, schrieb Dietmar Maurer:
>> where does this get printed / logged while the daemon is running?
>
> to 'stdout', which is likely to be /dev/null
>
> But If you use use 'pvesh' for testing, those messages will be printed to the console.

ah OK thanks!

>> Your wrote:
>>   >  # you need to get this working (fails currently, because>  # storage_migrate()
>> uses ssh to connect to local host (which is not>  # needed>
>> PVE::Storage::storage_migrate($cfg, $src_volid, $target_node,>  $target_sid,
>> $target_volname);
>>
>> So you think it makes sense to implement dd copying for SAN storage here too?
>
> Yes. We need a general mechanism to copy storage from A to B.

Correct but migrate is moving a volume right now and not copying.

Which situations do we have to handle?

OpenVZ:
- moving from the same to the same node doesn't make sense as it is only 
a directory and OpenVZ doesn't know more than a root fs
- copying can make sense so copying should work

KVM:
- moving from the same to the same node should work but we have to 
handle two situations.
    - 1. shared storage => just renaming the LVM storage to be now a 
member of VMID XYZ ?
    - 2. not a shared storage => moving does not work - except we dump 
image to local disk then copy via rsync and then restore the image to 
LVM disk.
- copying can make sense so copying should work

Do we have more situations? Does it make sense to make the dicision 
based on VM technology? I think it would make more sense to make it 
based on storage type?

Stefan