Amen!
Kelly J. Lipp VP Manufacturing & CTO STORServer, Inc. 485-B Elkton Drive Colorado Springs, CO 80907 719-266-8777 [EMAIL PROTECTED] -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of John Monahan Sent: Tuesday, June 20, 2006 1:35 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] TSM diskpool on SATA > Did you do any FILE devclass work? It sounds as though your miserable > performance was head thrashing, which we'd get in multiple LV DISK > devclasses, and also in FILE devclasses. Darn. :) No I was using a DISK devclass, but I'm almost positive it wouldn't have made any difference with FILE devclasses. Some of the LUNs were faster than others (first ones in the RAID group created) and as soon as I was writing to more than one at a time my performance would tank even further, which shouldn't be any different had I used FILE devclasses. I would have tried file devclasses with more time for performance reasons, but I had spent too much time on it already and the 150 MB/sec writes for my diskpool was adequate for my needs and outpaced the capabilities of my single Gigabit network connection to the TSM server, so I moved on. Hundreds of LVs with FILE devclasses on fibre disks would probably do exactly what you are looking for and provide excellent performance. SATA just isn't good enough at multiple, simultaneous I/Os to the same set of disks yet.
