Migrate to a bigger disk possible?

[Paul van der Vlis]

Thanks for your help!
Paul

Op 28-04-2020 om 07:39 schreef Peter Krempa:
> On Mon, Apr 27, 2020 at 20:58:19 +0200, Paul van der Vlis wrote:
>> Op 27-04-2020 om 10:41 schreef Peter Krempa:
>>> On Mon, Apr 27, 2020 at 10:13:37 +0200, Paul van der Vlis wrote:
>>
>>>> A point is that I have to create disk(s) on the other side with
>>>> qemu-img, I did not found a way to do that automatically. My question
>>>
>>> We are able to pre-create the storage given that a full copy is
>>> requested (copy-storage-all, not copy-storage-inc) and the images reside
>>> in a location covered by a libvirt 'directory' storage pool at least on
>>> the destination of the migration.
>>
>> Really interesting. I see an option "--migrate-disks" and I guess this
>> will do this. Something like:
>>
>> virsh migrate --live --p2p --copy-storage-all --persistent \
>>   --undefinesource --verbose ----migrate-disks vda \
>>   $vm qemu+ssh://$other/system
>>
>> Is there a way to simply migrate all writeable disks without specifying
>> them?
> 
> Yes. --copy-storage-all without actually using --migrate-disks. In the
> end --migrate-disks even requires you to specify either --copy-storage-all
> or --copy-storage-inc.
> 
>>
>>> Unfortunately we can't do it for incremental at this point.
>>
>> So far I understand it, incremental means something like a
>> synchronisation like rsync does. So parts what are allready there, don't
>> have to be copied again. Please correct me when I am wrong.
> 
> If you have a backing chain, that means an overlay image on top of the
> original base image e.g. a snapshot, then --copy-storage-inc copies only
> the overlay image, not all data.
> 
> Obviously if you have only one/base image then everything is copied. So
> if you meant to use a full copy, but got it just accidentally I suggest
> you use --copy-storage-all.
> 
>> When the disks are not there at the other side, an incremental backup
>> would be the same as a full copy.
> 
> No, that is not entirely so. This unfortunately has to do with external
> snapshots and it's most probably not documented clear enough.
> 
>>
>>>> was what would happen when I would create a bigger disk there then the
>>>> original one.
>>>
>>> I'm not sure now whether the new size will be picked up, but nothing
>>> should break, so you can give it a try. Certainly a shutdown and start
>>> of the VM will fix it if it's not picked up or a blockresize.
>>
>> Again thanks for your help!
>>
>> With regards,
>> Paul
>>
>>
>> -- 
>> Paul van der Vlis Linux systeembeheer Groningen
>> https://www.vandervlis.nl/
>>
> 
> 


-- 
Paul van der Vlis Linux systeembeheer Groningen
https://www.vandervlis.nl/