[Engine-devel] [vdsm] Snapshots with RAM feature

[Dan Kenigsberg]

On Wed, Apr 10, 2013 at 02:12:20AM -0400, Michal Skrivanek wrote:
> 
> 
> On 9 Apr 2013, at 10:01, Arik Hadas <ahadas at redhat.com> wrote:
> 
> > Hi All,
> > 
> > The proposed feature will make it possible to run a VM which was reverted to live snapshot
> > or created from live snapshot with the same memory state as it was at the moment the live
> > snapshot was taken.
> > 
> > http://www.ovirt.org/Features/RAM_Snapshots
> > 
> > All feedback is welcome!
> Nice!

(I prefer to inline the document when discussing it)

> VDSM changes
>
>    Default parameter will be added to vmSnapshot verb that maps string to string.
>        The map will include two keys for now:
>            'mode' that can be mapped to 'disks_only' or 'disks_memory' to
>                   indicate if memory state should be saved.
>            'memVol' that will be mapped to a string that represent the two
>                     volums that will be used to save the memory state and the
>                     VM configuration. The default map will include the
>                     mapping of 'mode':'disks_only' only.
>
>                     If the 'mode' value in the map decribed above is
>                     'disks_memory' the first volume in 'memVol' will be
>                     passed to libvirt in order to dump the memory to
>                     it, and the second volume in 'memVol' will be used
>                     to save the VM configuration (the same way it is
>                     done for hibernate operation).

This definition of 'memVol' would not allow saving the state to another
storage domain, or a direct lun or whatever.

I suggest that you have two independet arguments, say memVol and
vmConfVol. Both may have the standard pool-domain-image-volume quartet,
or a lun specification, or a local path.