Disk hotplug and snapshots

[Mike Kolesnik]

> Hi,
>  looking at the disk hotplug feature in the wiki I was wondering how
> that fits with the current implementation of the snapshots on the
> engine
> side.
> As far as I know the snapshots are at VM level now (no sigle disk
> snapshots),
> so what happens when you hotplug a new disk (no snapshots) into a VM
> that
> already has one or more snapshots? (and the other way around if
> possible).

What do you mean by 'hotplug'?
By feature description, the disk is always part of VM even if it's unplugged.
This is not the same as adding/removing disk to/from VM..

Snapshots should contain configuration which states if disk is plugged/unplugged - so if this configuration is present, it is used to determine the state of disks at that snapshot.

Snapshots also contain a list of the disks that existed when snapshot was taken, so adding a new disk will not affect old snapshots either way. 
You can then hotplug this disk, but this has no affect on existing snapshots.

When you unplug disk, it is still part of the VM and this also doesn't affect past snapshots.

> It might be worth documenting it in the wiki.
> 
> --
> Federico