dual Opteron AMD64 MySQL server performance/RAID card questions

[Josh Endries]

Hi all,

I have a shiny new dual Opteron system to mold into a MySQL server. The 
machine has a U320 10k 70 GB RAID 5 array (LSI MegaRAID 320-1), 2 GB 
RAM. I'm wondering the best way to go about this. I'm using FreeBSD 5 
(duh), actually 5.3-BETA7 right now, and the mysql41-server port. MySQL 
4.1 works out of the box, and I think is using both CPUs, yay! My method 
of testing this is running super-smack and watching top's kernel thread 
display, looking for CPU0 and CPU1 in the state column, though not 
necessarily at the same time (I don't think I've ever seen that). Not 
very realiable heh, but I dunno how else to check for that. I ran some 
tests using super-smack's select-key and update-select smack files, 100 
clients * 100 queries. I found that there was very little difference 
between MySQL 4.0 and 4.1, 4BSD and ULE, "-DWITH_OPENSSL 
-DBUILD_OPTIMIZED" and "-DWITH_OPENSSL -DBUILD_OPTIMIZED 
-DWITH_PROC_SCOPE_PTH". I got ~1330 and ~660 queries/sec, +/- 20, 
(respectively) for all kernel/build flag configurations. Probably all 
sorts of problems with this test, but I just wanted an idea if what it 
could do.

What I'm wondering is: are there any reasons to use one configuration 
over the other (ULE vs. 4BSD), or are there any other considerations for 
a server like this? Other optimizations? My other concern is the RAID. I 
haven't found any utilities or anything to monitor the RAID state and 
report or fix, rebuild, etc. without rebooting into the BIOS. Are there 
any SCSI RAID cards that support this in FreeBSD?

Thanks,
Josh