The Dell PERC H200 is a very basic RAID controller that does not have battery-backed cache, and therefore does not let you enable Write Caching within the OS. Writes using the H200 adapter can be very slow, so much that Windows Updates could take 2 to 3 hours on a RAID1!

To force enable write cache on an H200 adapter (at your own risk), do the following:

  1. Go to www.lsi.com and search for the latest MSM (or MegaRAID Storage Manager). At the time of this writing, it is 12.05.03.00. Install it, then run it.
  2. Log in to MSM using your local/domain admin credentials.
  3. Under the Logical tab, select the VD you want to enable write cache for, then right click and Set Virtual Drive Properties.
  4. Enable the write cache and accept all dialogs.
  5. Confirm write cache is enabled using Device Manager.

Keep in mind that this setting could cause data corruption if you don’t gracefully shut down your server during a disk write operation. What’s why it’s disabled by default and difficult to enable. Don’t leave this enabled on a production server…