Do you know if this paging is "real paging" or "Dataspace I/O": when using VM dataspace support in DB2, all DB2 I/O is done by CP paging, hence high page rates.
Quite some years ago, I created a document to explain the difference. It is called "Data in memory techniques" or alike and available on the VM web page. If you search for EXECLOAD, NUCXLOAD and, BUELENS you should quickly find it back. It contains an EXEC that you can run in a server every x minutes and that then will report how many real page in/out happend and how many dataspace read/writes (based on counts reported by CP IND SPACES) If you've got RTM/ESA, its DISPLAY SYSDASD command also reports the dataspace "paging I/O" Kris, IBM Belgium, VM customer support "Pohlen (Mailinglist)" <[EMAIL PROTECTED]> Sent by: The IBM z/VM Operating System <[email protected]> 2006-12-12 14:54 Please respond to The IBM z/VM Operating System <[email protected]> To [email protected] cc Subject problem with an old vm/esa environment after migration to a flex-es tserver Hi listers, I have a customer with a really old VM/ESA 2.2, VSE/ESA 2.3 and SQLDS database. Now after migration to the tserver he complains about performance problems. What I have figured out that he has massive paging only on SQLDS service machine (300-500 pages/s). This I cannot understand, because first he has more memory available as before on multiprise (193 MB vs. 768 MB now) and second we haven't changed the system layout compared to the multiprise. We have migrated the system by dump/restoring the volumes with DDR. So what can cause only the sqlds machine to page so heavily? I have already doubled the virtual memory to 96 MB but this had no effect on the behaviour. Does anybody have an idea, where I can search for the problem? Mit freundlichen Grüßen / best regards Franz Josef Pohlen
