We have recently virtualized 2 Server 2003 machines onto a Server 2008 R2 Hyper-V installation. The first one runs pretty well. It's a terminal server with about 20 users logged in. Performance is adequate although I wish it were faster. Users claim it is slower than their old box even though that one was nearing 10 years old. The second box is the domain controller that also handles Exchange and their database. It runs HORRIFICALLY slow. I think I've narrowed it down to the disk IO.
I know disk IO is the weak spot for VMs but what I'm seeing is beyond the pale. On the Terminal server we get roughly ~22MB/s of transfer speed copying a 1GB file from/to the same disk. Not very quick but it gets the job done. (It's probably
also why users feel it's slower) On the DC it gets ~4MB/s. I've checked everything I can think of. The IDE channels are in DMA Mode 2 on both Vms. I'd expect it higher but it's not as if it is in PIO mode. When copying files I
can see the Disk Queue Length spike up to around 30 (which seems a bit excessive). The MSDN library shows to use the Performance Monirot and check \Logical Disk\Avg Sec\Read and \Logical Disk\Avg Sec\Write. 1ms-15ms should be healthy. I show
a maximum of under 1 so that's fine. I've defragged (because it was heavily fragmented) and although it did help in accessing existing files (moving the needle from impossible to horrible), copying and creating are still the same. Integration services
are installed. Device Manager shows no issues. There are 2 VHDs connected. Each is a fixed size. No errors in the event log. Chkdsk is clean.
It also doesn't matter if I shut down either VM. It doesn't speed the other one up. In fact, I can do all-out 10GB copies inside of the each VM at the same time and still copy files in the host at over 200MB/s both read and write while that is
going on. These are 4 drives in RAID 6 that top out at over 300MB/s in both read and write in the host.
Any advice would be great. Thanks!