Enabling Write Cache on PERC H200

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 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…

10 thoughts on “Enabling Write Cache on PERC H200

  1. My interpretation of “The Dell PERC H200 is a very basic RAID controller” is “The Dell PERC H200 is a crap RAID controller”. Does that sum it up?

  2. Hi Gonzalo, i have installed the version you mentioned above. But i don’t get the same login screen you do. My one just goes straight to the console and then says there are no servers found even when it has the correct IP address. I repaired the installation installing everything and then it said there were no controllers found.

    1. It would only cause data loss if you don’t properly “flush” the cache by shutting down the server properly, or making sure all writes are committed. I would discourage from changing this setting on a production server that has no battery backup and won’t shut down automatically on battery power.

  3. You actually can enable write cache using the basic management software that comes with the Dell server. Log in, Select System > Storage > PERC H200 > Virtual Disks. Then on the right hand side, choose form the drop down menu “Change Policy” then execute. Choose to have Write Cache enabled, apply settings. This instantly made writes as fast as my reads up to 2048 chunks. As noted before, do NOT enable this on a server unless you have a UPS device and automatic shutdown is set up on the server.

  4. Old thread I know, but if somebody has the same problem like Matt, just type instead of the ip address. Then you should be able to connect to the local host with the megaraid storage mamager…

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