- Posted by ploft on March 20, 2009
I've been running with Windows 2008 for quite some time now, and at the time where DPM 2007 was released I guess Windows 2008 still was kind' a new to people, so no resolution or scenario of this issue was right at hand at the time.
System:
HP ProLiant ML 110 powered by Intel Xeon CPU with 8 Gb memory running 64-bit version of Windows Server 2008 Enterprise (Hyper-V role enabled) with SP1 and all latest updates.
Used quite some time searching the web for a resolution to this problem, and most people a who I "ran into" suggested that I should wait for the SP1 for DPM 2007. Doing some more digging it turns out that the Virtual Disk Service (VDS) on the older 2000 and 2003 system had some memory leaks, and kb-articles referring to these scenarios looked a lot like the problems I have on my Windows 2008 system. Chances for an error reoccurring could therefore be somewhat expected. Not key on manually overwriting important system files on a semi-working system which handles backup, I first of all turn to my patience willing to give the SP1 a chance to might fix this issue since Microsoft at this time doesn't have any fixes ready yet.
SP1 came and a lot of improvement in speed generally, but I still see the VDS service consume way to much memory most of the time, but the applications is more responsive and therefore gives a better user experience speed-wise.
In the lack of better suggestions I turn to the physical hardware and installs further 4 Gb memory, maxing out the total memory possible for this machine 8 Gb. Once again it helps - but only for some time. Hence the amount of backup jobs and data being stored, the system slowly grinds back to the same sluggish state that it had in the beginning.
Getting more and more errors and failed backup messages, and I'm guessing the VDS memory leak is affecting the DPM and its ability to successfully backup things.
Today I stumbled over this kb-article:
http://support.microsoft.com/kb/958387
"On a computer that is running Windows Vista or Windows Server 2008, a memory leak may occur in the Virtual Disk Service. This problem may occur in the following scenarios.
A memory leak occurs in the Virtual Disk Service when an application uses the Virtual Disk Service to enumerate disk resources. In this scenario, you notice that the memory consumption of the Virtual Disk Service (Vds.exe) increases continually."
Once again - sounds exactly like what I'm experiencing, and this time it's for Windows 2008 - yes baby!
Installed the fix (kb958387) and have been running with this update for a week now, backup jobs are hitting a much higher successful rate than before, and whereas the machine often was slow after just one day in companionship with memory-leaking-VDS. VDS and DPM seems to be better friends now and I don't see any huge unexpected memory usage anymore.
I've been running a couple of weeks with this fix, and yes no more memory slaughtering from the VDS service. Thought I'd just share this with you, so none of you should experience the same annoying scenario with a sluggish DPM server or other backup products using Volume Shadow Service (VSS).