Windows 7 - Backup Using Child Partition Snapshot and Backup Using Saved State

Asked By wjvi on 23-Jan-09 09:01 PM
I have noticed after installed DPM 2007 SP1 and the Hyper-V Host updates that
I have different choices for backing up Hyper-V guests. Is there a whitepaper
or something that explains the differences between these two choices of
Hyper-V backups and why one option or the other is available for the
different virtual machines.

Thank you in advance.




Narendran Gunasekaran[MSFT] replied on 27-Jan-09 12:11 AM
Hello there,
If at least one of the following conditions is true, DPM cannot backup a
Hyper-V VM in online(running) state:
1) The integration components for volume snapshot copy disabled for theVM
2) Dynamic disks configured inside of the VM
3) Non-NTFS based partitions inside the VM
4) Changed shadow storage assignments within the VM.
5) VM is not in running state.
In such a case, the VM is put into saved state before the host volumes are
snapshotted for back up. For such VMs, HyperV writer reports the VM
datasouce name in the format "Backup Using Saved State\<VMName>". If online
backup is possible for a VM, the format will be "Backup Using Child
Partition Snapshot\<VMName>".

Note: DPM saves the name of the VM only when the VM is added for protection,
and it doesn't update it at any point later. Therefore, if initially a VM
doesnot meet the conditions for online backup when added for protection, but
at a later point of time the VM's configuration is changed such that online
protection is possible, the display name won't be changed. (But online
backups will be taken from then on.)

--
Thanks
Narendran
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
ClaudioG64 replied on 28-Jan-09 08:41 PM
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Hello Narendran,
what about passthrough disks ? Are they supported with DPM ?

Thanks, Claudio
Narendran Gunasekaran[MSFT] replied on 28-Jan-09 12:40 AM
Hi Claudio,
A VM with pass-through disks can be backed up, but the pass-through disks
will be ignored.

--
Thanks
Narendran
Disclaimer: This posting is provided "AS IS" with no warranties, and
confers
no rights.

On Jan 27, 6:11 am, "Narendran Gunasekaran[MSFT]"

Hello Narendran,
what about passthrough disks ? Are they supported with DPM ?

Thanks, Claudio
wjvi replied on 30-Jan-09 03:35 PM
Narendran,

If you remove and re-add the VM will the name change to show the change?

How can I tell how it is being backed other than the name. In my case I
think it was because the VM didn't have the VS Writer 940349 installed in the
guest OS and now I have it installed. That was the only difference I could
find between a VM that did online backups and one that didn't but if the name
doesn't change I do not know how to be sure.

A utility from the DPM team to check a VM guest for online backup abilities
and report any reasons it cannot be backed up would be great. Even if you
have to run it from inside the VM it would be nice to have.