Slow Hyper-V backups in BE2012.
We're currently testing BE2012 in a new Hyper-V cluster environment; however, the backup speeds leave much to be desired. We're interested in Full/Inc backups via the host with GRT and have tested using disk (with and without compression) and de-dup. The tape drives are on the production BE2010 server, so B2D-to-tape hasn't been tested. The agent is installed on all Hyper-V hosts in the cluster and on 4 test VMs (each with a basic Server 2008 install).
In testing, each VM backup took approx. 15min via the host, irrespective of Full or Inc. As they run in series, the job took approx. 1hr. Multiple tests were run using disk, compression and de-dup; however, there was little difference in time. Considering the cluster will eventually have about 100 VMs, 15min/VM in series is simply too slow, especially considering these servers don't have any applications installed and aren't in production.
In contrast, the VMs were backed up directly via the agent. In this scenario, all 4 backups ran concurrently and completed in about 8min. The problem when backing up via the host is that the pre-processing/queuing/snapshot/etc always takes at least 10min, whereas the actual data copy occurs in <5min at ~2-3GB/min. Any assistance in resolving this issue would greatly appreciated; even if the solution is simply to backup the VMs directly!
DPM (which is also being tested) takes about 3min to backup each VM.