Re: [pve-devel] [PATCH v4 qemu-server 2/2] remote-migration: add target-cpu && target-reboot params

[Fiona Ebner <f.ebner@proxmox.com>]

Am 10.10.23 um 18:29 schrieb DERUMIER, Alexandre:
>>
>> I think that a true offline migration (without starting any
>> source/target vm) can be done with qemu-storage-daemon running nbd
>> server on target &&  qemu-img on source.
>>
>> This could be also used for online migration with unused/detached
>> disks.
>>
> 
>>> Yes, we could, but would require additional logic. So the question is
>>> if
>>> there are enough advantages to do it rather than via a full VM.
>>> Starting
>>> a VM of course requires more resources.
> 
> I don't known if it's possible to use the ndb server in the targetvm,
> if the target disk is not attached ? (I really don't known)

Yes, I think need to attach it as a blockdev first. But for 'restart'
migration, it should be fine to start out with NBD and migrate
non-attached disks with our current method. If we (later) want to add
logic for migrating non-attached disks via storage-daemon we can always
do that too and switch storage_migrate() to use that (maybe not
unconditionally, ZFS -> ZFS still makes more sense to do with send/recv
for example).