We have a very large VM system that runs in a partition on a Z9 with 7 dedicated processors and 24G/4g stor/xstor
We can, at peak times, get up to the upper 9x% level but this week we have been running in the 60-75% range Earlier this afternoon I had a user complaining about performance and I could see the following (notice PROC 0000) :- AVGPROC-062% 07 XSTORE-000000/SEC MIGRATE-0000/SEC MDC READS-000001/SEC WRITES-000000/SEC HIT RATIO-100% PAGING-1/SEC STEAL-000% Q0-00004(00000) DORMANT-00253 Q1-00018(00000) E1-00000(00000) Q2-00006(00000) EXPAN-002 E2-00000(00000) Q3-00048(00000) EXPAN-002 E3-00000(00000) PROC 0000-082% CP PROC 0006-057% CP PROC 0001-059% CP PROC 0002-059% CP PROC 0003-060% CP PROC 0004-059% CP PROC 0005-059% CP LIMITED-00000 Ready; T=0.01/0.01 13:23:56 I have seen this behaviour before when :- a) The system is very busy and we are approaching 100% keeping the scheduler over employed. b) We are getting streaming CP messages (i.e. device retries). c) Huge amounts of data are being spooled from some userid I have checked and, as far as I can tell, none of these were relevant at the time. Can anyone suggest any other likely conditions that would cause such a heavy overload on processor 0? btw: The situation improved (with an even balance of processor usage being restored) over a period of about 45 minutes. Colin Allinson VM Systems Support Amadeus Data Processing GmbH
