LSI Megaraid (amr) performance woes

Doug Ambrisko ambrisko at
Wed Mar 1 22:09:02 UTC 2006

Sven Willenberger writes:
| On Wed, 2006-03-01 at 15:08 -0500, Mike Tancsa wrote:
| > At 02:10 PM 01/03/2006, Sven Willenberger wrote:
| > 
| > >I cvsupped a 6.1 prerelease and found no performance improvements. I did
| > >some further tests and the performance issues seem very specific to the
| > >mirroring aspect of the raid:
| > 
| > 
| > I am not familiar with the LSI cards, but with older 3ware and the 
| > ARECA cards, the raid sets when in any sort of redundancy mode must 
| > initialize in the background before normal use.  Until that is 
| > complete, performance is seriously slow.  Is the LSI doing that, and 
| > perhaps just not telling you ?
| I had thought of this too so I disabled the rapid (background)
| initialization option and let the raids build to completion the slow
| way. So unless it is still building even after it is done (or is doing
| some other odd processor-intensive crc checking or something) I don't
| think this is the source of the problem.

If you run the Linux MegaMon utilties it will tell you if the 
controller is running background tasks like this and tell you the

Doug A.

More information about the freebsd-stable mailing list