Thanks Norman, I was wondering at what point I should consider specifying the LFAREA value. Here's an update to our 64-Bit storage / poor performance issue: I didn't mention this before, but our periods of poor performance was due to SRM overhead as it searched for available above the bar frames and performed frame stealing in order to bring the 1MB (per logical CP) system trace buffers into core to process each abend. One of IBM's recommendations was to either drop our central storage allocation from 4GB to 2GB or add more. We felt that dropping back to 2GB would cause memory constraints below the bar, so last weekend I added 1GB to the test LPAR bringing the total central storage allocation to 5GB. The abend scenario that would typically cause the slow down condition has been frequently tested since then and here we are at the end of the workweek and the slow down condition has not reoccurred. So adding more memory has solved our problem just as described in II14465. It depends on how much above the 2GB bar central storage you have allocated and what you have running that's exploiting that 64-bit storage as to whether you'll have this problem or not. If you have configurations similar to ours, watch out for this one when you upgrade to z/OS 1.10/1.11. Jack
>>> Norman Hollander on DesertWiz <[email protected]> 3/19/2010 >>> 12:40 AM >>> Unless you have DB2 v10 or Java 6 SP3, there is no value to specifying LFA. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Jack Oakley Sent: Wednesday, March 17, 2010 SYSN 03:52 AM To: [email protected] Subject: Re: 64-Bit Storage / Performance Issues with z/OS 1.10 No LFAREA specified in IEASYSxx so taking the default (no real storage used to back 1M pages). >>> Gil Peleg <[email protected]> 3/17/2010 5:44 AM >>> Jack, What value do you specify in IEASYSxx for LFAREA= ? The default is none, which means no real storage should be used to back 1M pages. So if you are taking the default, your problem is probably not caused by large pages. HTH, Gil. On Tue, Mar 16, 2010 at 7:17 PM, Jack Oakley <[email protected]> wrote: > Curious to learn if anyone else has experienced this problem and what you > did to resolve it. > > Migrating from z/OS 1.9 to 1.10. z/OS 1.10 exploits more 64-bit storage > (GRS, SMSPDSE, TRACE, etc). The system trace (TRACE) buffers not only > increased from 256K to 1M per logical CP, but also moved above the 2GB bar. > We are experiencing very poor performance mostly during abend processing as > described in II14465. > > Configuration: > LPAR has 4GB real storage. > 2 logical CPs > > In addition to z/OS, significant exploiters of 64-bit storage are: > Four DB2 v8/v9 systems > Three IMS v10 systems > Four CICS Transaction Server v3.2 regions > Two Java 1.6 (64-bit) application address spaces > > Regards, > Jack Oakley > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
