I have an SQL Server 2000 DB running on a 5 year old server. It has 5 drives SCSI 10KRPM drives on IBM ServeRAID 4Lx card. I'm maxing it out to 9 on the same backplane (all 10KRPM).
Not sure the best way to make them count. Here's the particulars:
1. Current config is:
Vol1 = RAID1 for OS, swap, and Logging files.
Vol2 = RAID5 (3 disks) for DB.
2. The app does heavy writes and use of Temp DB.
I don't have by-volume stats. This stat excludes backup (taken 3 hours after a daytime reboot). Windows Task Manager shows SQL task and SERVICES.EXE both have physical reads about 15% higher than physical writes. SERVICES.EXE has about 3x the IO count as the SQL task. I assume that's mainly SQL activity.
Thanks so much for the replies! Great link ReadySetStop.
Jeebustrain - it's not a capacity hit since I get the capacity of 2 drives with either 4-disk-RAID10 or 3-disk-RAID5. It does make me realize my existing RAID5 uses 32GB drives that aren't commonly available anymore. I think that's OK, the bigger drive should downgrade to 32. With a 4GB database, even 32 x 2 is plenty of space to allow for expansion.
As that link indicates; SQL IO tuning is a deep subject and lacking real data it shouldn't be over-thought. Performance assumptions are too often wrong.
I'll take your advice and go with Option 3, unless I can find a compatible external solution I can transfer to the next server - probably within 6-12 months (no time right now for the 64 bit testing process). IBM's external solutions all require PCIe slot or list my current server (IBM x235) as incompatible.
So; it's a $2000 band-aid that'll get the log files off the OS drive and convert the data volume from RAID5 to RAID10. Should help considerably and is the least risky (4 disk RAID10 is known to always trump a 3 disk RAID5 - not the more risky replacement of RAID5 with RAID1). If I decide to spend more on this server; converting the remaining drives to 15K RPM wouldn't even require downtime - just $1500 in drives (I realize all drives downgrade to lowest speed on backplane).
Last edited by vich; 04-03-08 at 18:13.
Reason: added final comment