You've gotten some good input, but I'd like to recommend dumping Raid 5 altogether. With several clients I've seen significant performance increases from switching from (recommended) Raid 5 arrays to what may be referred to as Raid 10 (Raid 0+1/1+0) arrays. This type of array mirrors pairs of striped disk arrays (or vice versa) and will definately perform better than a Raid 5 array. I don't recall specific numbers, but do remember clients smiling after making the change where frowns which your client apparently now have.
Raid 5 uses a parity 'disk' which requires multiple reads and writes for each disk I/O operation. Removing that overhead alone will boost performance by as much as 8 to 20 percent, depending on the configuration and how many spindles are affected. Also, it might be worth the time to change the uvconfig parameters that affect SELECTs starting with the location of UVTEMP as previously recommended. I always do that for my clients as part of an install so if the tmp files need to be removed, /tmp doesn't have to be messed with. Another one is the SELBUF setting, which determines how much of a select is done in memory before going out to disk. Setting this higher can improve performance especially where disk I/O is suffering. FSEMNUM, GSEMNUM and PSEMNUM are other settings you may want to adjust to see if disk I/O will improve. There is one other issue with AIX you may be experiencing. For some reason, some sessions attached through TCP/IP links 'go away' and leave the session open. I have to use the TANDEM function to check those processes. They are usually at some prompt cycling through whatever they are doing as though someone is sitting at a keyboard with a book leaning on the ENTER key causing it to repeat over and over. AIX has the 'w' command which shows CPU time chunks each user has. There are 3 columns and if the 2nd or 3rd column is high and the first is 0 then that session is a candidate for having problems. One major clue something like this is happening is if the results of the uptime command show numbers unusually high. But all in all, you've gotten some good suggestions already and I may be up in the night, so to speak. Karl On Thu, 2004-04-08 at 13:18, Kevin Vezertzis wrote: > Thanks for all of the posts...here are some of our 'knowns'... > > 1.) Application files have all been analyzed and sized correctly. > 2.) IBM U2 support analyzed Universe files, locking, swap space and all > have been adjusted accordingly or were 'ok'. > 3.) We are running RAID 5, with 8G allocated for Universe > 4.) We are already running nmon, which is how we identified the paging > faults and high disk I/O > > 4.) Attached you will find the following: > smat -s > LIST.READU EVERY > PORT.STATUS > Uvconfig > Nmon (verbose and disk) > Vmtune > > I know this is a lot of data, but it is a mix of what each of you have > suggested. Thanks again for all of the help. > > Kevin > > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of Kevin Vezertzis > Sent: Thursday, April 08, 2004 12:08 PM > To: [EMAIL PROTECTED] > Subject: Performance > > We are looking for some insight from anyone that has experienced > performance degradation in UV, as it relates to the OS. We are running > UV 10.0.14 on AIX 5.1.we are having terrible 'latency' within the > application. This is a recent conversion from D3 to UV and our client > is extremely disappointed with the performance. We've had IBM hardware > support and Universe support in on the box, but to no avail..we are > seeing high paging faults and very highly utilized disk space. Any > thoughts or suggestions? > > Thanks, > Kevin > > ______________________________________________________________________ > -- > u2-users mailing list > [EMAIL PROTECTED] > http://www.oliver.com/mailman/listinfo/u2-users -- Karl L. Pearson Director of IT, ATS Industrial Supply Direct: 801-978-4429 Toll-free: 888-972-3182 x29 Fax: 801-972-3888 http://www.atsindustrial.com [EMAIL PROTECTED] -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users