[PVE-User] Bug when removing a VM

[Ronny Aasen]

On 21. juni 2018 11:17, lemonnierk at ulrar.net wrote:
> Mounting it read only doesn't allow easy migration between clusters,
> which is the goal here. Unless someone knows a better way to migrate a
> VM from a cluster to another without more than a few seconds of
> downtime, but that's the best I could come up with
> 
> On Thu, Jun 21, 2018 at 10:43:53AM +0200, Dietmar Maurer wrote:
>> In general, you should never mount storage on different clusters at the same
>> time. This is always dangerous - mostly because there is no locking and
>> because of VMID conflicts. If you do, mount at least read-only.
>>
>>> Not sure this is a bug, but if it's not there should be a huge red
>>> warning in the VM removal box, I think.
>>>
>>> We've been migrating some VMs between clusters, and for that I mounted
>>> the old storage on the new cluster,
> 


personally i use a third storage, dedicated for migrations. anything 
that both clusters can use is ok. i often use a CEPHFS directory, or a 
NFS share.

connect the third storage to both clusters.
migrate a vm from normal to migration storage on the "FROM" cluster.
create the vm on the "TO" cluster.
stop the vm on from, and start on TO.
and move the disk from migration storage to TO clusters normal storage
delete vm from FROM cluster.

this way the TO storage does not see the FROM storage's normal storages. 
and they can not delete disks between them.

i also use this same migration storage for imports from other systems 
(p2v/vmware/hyperv),

kind regards
Ronny Aasen