[pve-devel] [PATCH] Implement pending change

[Dietmar Maurer]

> >>Or what is the advantage to allocate immediately?
> 
> Because we can do hotplug.
> So I create the disk, put in pending.
> Then if hotplug fail, we keep the device in pending.
> 
> (I could even be possible to always enable hotplug by default with this method)

OK

> >>And why do you want to maintain a list of unused disks inside [PENDING]?
> 
> because we can delete and add a new disk on same id. (or swap it) If I don't
> maintain a list of unused disk and use delete:
> 
> 
> [CONF]
> virtio0

[CONF]
virtio0: local:100/vm-100-disk-1.qcow2

> 
> -delete the disk
> 
> [CONF]
> virtio0
> [PENDING]
> delete : virtio0

[CONF]
virtio0: local:100/vm-100-disk-1.qcow2
[PENDING]
delete : virtio0

> now add a new disk on virtio0
> 
> [CONF]
> virtio0: new disk
> [PENDING]
> delete: virtio0

[CONF]
virtio0: local:100/vm-100-disk-1.qcow2
[PENDING]
virtio0: local:100/vm-100-disk-2.qcow2

> So, what happen here ? I lost the reference of previous disk, and I will delete the
> new disk on pending commit.

See my example - I do not lose any reference.