SSD for Hyper-V Build Lab

Posted on July 25, 2010

Turns out Computer Plaza here in Dubai is not as well stocked as this geek would like: two visits and still not able to find a RAID card with an on-board cache. And the RAID cards they do have I can’t find online, so no telling whether they would work on Windows Server 2008 R2, being 64bit and all.

Plan B: an SSD. And not through USB, I have an Express card to add eSATA to my laptop.

Trying to be clever, I then mounted the SSD as a pass-through disk under Hyper-V, just to get that extra little speed…

Installing Windows Server 2008 R2 takes about 7mins! (via the Express card eSATA onto  the Kingston v+ 128GB SSD).

And Hyper-V has this cool feature where when you create a new VHD, you can create it “from” a physical disk: Hyper-V will copy the content of a drive into a VHD:


The VHD file was being created on a 7200RPM 500GB disk placed in the laptop’s media bay. Task Manager’s Resource Monitor suggested that write operation was running about 44 million bytes per second.

The Catch, unfortunately, is that Hyper-V seems to make a raw copy of the disk, not paying attention to the fact that most of that pass-through disk ended up being empty. So I ended up waiting almost half an hour for Hyper-V to read the entire 128GB SSD (perfmon showed 114 million bytes per second read activity on the SSD for the duration), only to end up with a 6.5GB dynamically expanding VHD.

With the up-front time saving blown away, I then tried installing Windows Server 2008 R2 into a dynamically expanding VHD file that was created on the SSD. That took a little longer than the original 7mins, but copying the resulting VHD took only 3mins, so the lesson is that unless you’re going to fill that pass-through disk, you may be better off paying the perf cost during installation: from 7mins to 9mins on my laptop.

Posted in: Lab Management