Hyper-V and DPM – snapshot problem
Piotr
virtual machines. After couple of months and installing patches I have got it
finally running without crashing servers.
However I noticed that DPM create local (on disk where virtual machine is
stored) snapshot which I’m not able to see on Hyper-V management console. My
problem is that snapshot growth very fast and now on one HDD I’m almost out
of space (93% used).
My questions are:
1. How can I merge snapshots to VM – is it enough to shut down it?
2. How to avoid problems like that in future
3. What will happen when snapshot will reach whole space on the disk?
Could you advice me please? It is kind of urgent as I’m not quite sure if
after next backup my MV will work.
Praveen D [MSFT]
DPM creates a Volume based VSS snapshot of the volumes where VHDs
are present. Where in case of hyper-V it creates snapshot by creating an
additional Virtual HardDisk file(.vhd file). These are completely different
to each other hence DPM snapshots will not be seen in Hyper-V role.
Moreover, DPM deletes the snapshot at the end of the backup. This can be
easily verified, by running vssadmin list shadowstorage /for=C: (assuming C:
is there VHD files are present)when DPM backup is in progress, it shows the
disk space being used by VSS snapshots. At the end of the backup DPM deletes
this snapshot hence the disk space will be claimed back, you can run
vssadmin list shadowstorage and verify it.
Coming to specific questions:
> My questions are:
> 1. How can I merge snapshots to VM – is it enough to shut down it?
Its not possible to merge DPM snapshots with VM snapshots.
> 2. How to avoid problems like that in future
My guess is your Hyper-V snapshots are taking too much of disk space, you
can merge the snapshots using Hyper-V console. You can also verify the disk
space being used by DPM vss snapshots by running vssadmin list shadowstorage
/for=C:.
> 3. What will happen when snapshot will reach whole space on the disk?
When disk is out of free space, Hyper-V stops Virtual machines. But if it is
happening due DPM VSS snapshots, VSS will delete those snapshots and create
the free space. At any time you can verify the VSS snapshot disk usage by
running vssadmin list shadowstorage /for=C:.
Hope this helps you.
Thanks,
Praveen D [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights
"Piotr" <Pi...@discussions.microsoft.com> wrote in message
news:63BDE7AE-CBF9-4EDF...@microsoft.com...
Narendran Gunasekaran[MSFT]
Yes, as Praveen D has mentioned below, DPM takes VSS snapshots while backing
up VMs, which is in no way related to Hyper-V VM snapshots. DPM doesn't
create, or do anything with regard to Hyper-V VM snapshots.
Please check if you have any other app that would have created Hyper-V VM
snapshots. And yes, after deleting the Hyper-V snapshot from Hyper-V manager
console, you will have to shutdown the VM for the merging to take place.
(This is the Hyper-V behaviour.)
If you figure out why and how Hyper-V snapshot was created automatically in
your system, please do let us know. And what is the size of the snapshot
(.avhd files) in your system now?
(Additional info: DPM will continue to do backups of VMs even in the
presence of Hyper-V VM snapshots, and is supported.)
--
Thanks
Narendran G
This posting is provided "AS IS" with no warranties, and confers no rights
"Praveen D [MSFT]" <prav...@microsoft.com> wrote in message
news:e8PRzYCk...@TK2MSFTNGP06.phx.gbl...
Piotr
Many thanks for your help. I will check how my snapshot works on my servers
as I can see some mess (probably some deleted but not merged).
Your posts were really helpful as I know how it works now.
Once again many thanks.
"Narendran Gunasekaran[MSFT]" wrote:
> .
>
Piotr
Many thanks for your help. I will check how my snapshot works on my servers
as I can see some mess (probably some deleted but not merged).
Your posts were really helpful as I know how it works now.
Once again many thanks.
"Praveen D [MSFT]" wrote:
> .
>