We migrate three OS/390 system from 2064-2C1 running on native LPAR mode to 2098-T01 running under z/VM like the below.
HW: z10 BC- 2098 T01 (GCP 1 EA) OS: z/VM V6.1 Guest OS: Four OS/390 v2.10 (SE02, SE05, SE06, CF) running under z/VM 1) Between three OS/390 guests share many DASD which are defined by full-pack minidisk in CP directory. 2) three OS/390 guests share the DASD using GRS. MIM is used before migration 3) three OS/390 guests are coupled by Sysplex(VCFLINK under z/VM) thru CF guest 4) Sysplex(XCF) is used for only GRS and Tape sharing. MIA is used before migration 5) GRS was not used befor migration * Problem Symptom => During night time, batch job workload on SE02 was taking too long and SE02 Guest system has high CPU usage(Specially Supervisor CPU% is high around 32% and Emulated CPU% is 35%) and I/O wait(12%) by performance toolkit. => By monitoring in OS/390(SE02), CPU Usage of MASTER, GRS, CATALOG task is high. therefore batch job is hard to get CPU resource. => CF Guest user has only 1% of CPU utilization. => batch job use DASD and Tape devices. could it be caused by VM side or OS/390? What do we need to check more to find what is root cause and to fix this problem?
