FYI: Tuning AIO Servers AIX uses asynchronous input/output (AIO) servers to perform asynchronous I/O to the disk subsystem. Using AIO can greatly improve SSA performance because the server doesn't have to wait for the I/O to complete. For example, to check or change your settings: [EMAIL PROTECTED]:/>smitty aio Select Change / Show Characteristics of Asynchronous I/O The minimum number of servers is the number of AIO servers that get started at system boot; the maximum number of servers is the maximum number of servers that will run on that machine. When you are starting, your tuning maximum should be set to the number of disks performing AIO times 10. Minimum should be set to maximum divided by 2. To find out how many AIO servers you currently have running, use: pstat -a | grep -i aios | wc -l If this number equals your minimum value, you may be able to reduce the number of AIO servers. If it equals your maximum, you may need to increase the number of AIO servers. If it is between your minimum and maximum, no changes should be required.
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] 28-May-04 10:59:11 AM >>> But what I remember is there is limit for no: of aios any ideas? -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Paul Zarnowski Sent: Friday, May 28, 2004 10:45 AM To: [EMAIL PROTECTED] Subject: Re: aix and aio? It is allowed. It was recommended to us. We use it here on our AIX server. I can't say whether it helps or not, but it doesn't seem to hurt. At 09:10 AM 5/28/2004 -0500, Mike Eggleston wrote: >Is aio suggested/recommended/allowed on AIX? Is anyone >using it? Does it help? My current tsm server is AIX >5.2-ML2, 2GB core, lots of ssa disk (though I've requested >more to increase the local storage pool to the size of the >nightly incremental backups), and four fiber connections >directly to tape drives (3590?). > >Mike -- Paul Zarnowski Ph: 607-255-4757 719 Rhodes Hall, Cornell University Fx: 607-255-8521 Ithaca, NY 14853-3801 Em: [EMAIL PROTECTED]
