Hi Miles, Paul Zarnowski and others who responded to my question! Just to let you know the status of my performance problem: we converted the database RAW LV's to JFS and we enabled AIO and direct I/O. This caused CPU wait to go down from an average of 40% to about 25%. Sequential I/O rate measure outside of TSM went up from 10 Mb./sec. to around 40 Mb./sec. But TSM does not benefit from this at all. We checked everything outside of TSM, so I will now create a software call at IBM. The database itself has to be the bottleneck. Again, thank you VERY much for all your help!!! Kindest regards, Eric van Loon KLM Royal Dutch Airlines
-----Original Message----- From: Miles Purdy [mailto:[EMAIL PROTECTED] Sent: Wednesday, February 02, 2005 19:04 To: [email protected] Subject: Re: SSA Disk performance Hi Eric, I'd like to help you out. Check this out first: http://www.samag.com/documents/s=1146/sam0109j/0109j.htm And maybe contact me offline and I will see what I can do. Miles ---------------------------------------------------------------------------- ------------------ Miles Purdy System Manager Information Systems Team (IST), Farm Income Programs Directorate (FIPD), Agriculture and Agri-Food Canada (AAFC) 6th Floor 200 Graham Ave. Mailing: PO box 6100 Winnipeg, MB, CA R3C 4N3 R3C 4L5 Office contact: Mobile contact: [EMAIL PROTECTED] [EMAIL PROTECTED] ph: (204) 984-1602 fax: (204) 983-7557 Cell: (204) 291-8758 "If you hold a UNIX shell up to your ear, can you hear the C?" ---------------------------------------------------------------------------- --------------------- >>> [EMAIL PROTECTED] 02-Feb-05 10:39:19 AM >>> Hi *SM-ers! We are currently struggling with our SSA disk performance. For some strange reason we see that although all disks use LVM mirroring, the reads are not balanced. In most case one disk is used for 60 or 70% while it's mirror is just using 3%. We also measured the disks performance. We created a file on a raw logical volume and measured around 15 Mbytes/sec. We created a JFS filesystem on the same disks and reran the test: 40 Mbytes/sec. I cannot explain this difference! RAW should perform better that JFS on AIX 4.3.3, right? Today we upgraded AIX to the latest maintenance level (11) and installed the latest firmware on the disks, but performance hasn't improved. I was hoping that TSM-ers with AIX performance knowledge can help me out here, I'm stuck right now... Thank you VERY much in advance for any reply!! Kindest regards, Eric van Loon KLM Royal Dutch Airlines ********************************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. **********************************************************************
