Comments on: Hyper-V pass-through disk performance vs. fixed size VHD files and dynamic VHD files in Windows Server 2008 R2

By: Migrating Hyper-V VM with pass thru disk - should this work?

Migrating Hyper-V VM with pass thru disk - should this work? — Thu, 29 Mar 2012 14:22:30 +0000

[...] Strike that, less than a few percent performance loss on some areas and gains in others: Hyper-V pass-through disk performance vs. fixed size VHD files and dynamic VHD files in Windows Serv… Hyper-V pass-through disk performance vs. fixed size VHD files and dynamic VHD files in Windows [...]

By: Dario

Dario — Mon, 05 Sep 2011 23:01:06 +0000

Thanks this was exactly what I was looking for. No pass thru disks needed it seems.

By: Joe

Joe — Thu, 04 Aug 2011 08:42:29 +0000

Problem with dynamic disks.

If you have more than one dynamic disk per partition then you will run into fragmentation issues when they automatically expand and take up the next space on the disk. you will have something like;

I’d use Fixed size VHDs and where possible keep them to their own physical disk volumes.

By: 2010 in review « Clustering For Mere Mortals

2010 in review « Clustering For Mere Mortals — Mon, 03 Jan 2011 18:17:35 +0000

[...] Hyper-V pass-through disk performance vs. fixed size VHD files and dynamic VHD files in Windows Serv… September 200910 comments 4 [...]

By: James

James — Tue, 14 Dec 2010 02:50:01 +0000

By: daveberm

daveberm — Wed, 10 Nov 2010 00:13:55 +0000

Sorry, not sure what the problem might be. Do you have a NIC dedicated for iSCSI?

By: Scott

Scott — Mon, 08 Nov 2010 15:19:57 +0000

I’m new to IOMeter, Is there something that needs to be done on the Windows 2008 R2 server to see the iSCSI Disks?

I can see all of them on the Windows 2003 servers, just not the 2008 R2 servers. Local and network drives show up fine.

Thanks,

By: daveberm

daveberm — Sat, 20 Mar 2010 01:20:30 +0000

Microsoft has gone and published their own report. Have a look at it here…

http://download.microsoft.com/download/0/7/7/0778C0BB-5281-4390-92CD-EC138A18F2F9/WS08_R2_VHD_Performance_WhitePaper.docx

By: daveberm

daveberm — Sat, 05 Dec 2009 00:27:45 +0000

I have not done any comparisons of R1 and R2 and have not tested booting from fixed vs. dynamic disks. I always boot from dynamic disks in my lab and have not noticed any apparent delay. Let us know if performance improves for you.

By: Ryan

Ryan — Sat, 05 Dec 2009 00:08:00 +0000

I’m getting much slower boot time (2x-3x or more) after exporting a VM (and converting the fixed disks to dynamic) from a Hyper-V r1 host to an R2 host. I haven’t had a chance yet to test the same VMs if I kept them as fixed disks. Have you also seen this behavior? I haven’t had a chance to test performance after boot, though….