Your DBA's are not even close. Unless the DB2 address spaces are waiting for DFHSM services(unlikely), faggedabouditt! Your normal tuning should insulate DB2 from any vagaries of DFHSM processing.
IMO the most likely cause (if there is DASD interference) would be in the cache. I don't know if EMC has the ability to "fence" the cache for workload separation(open systems vs. z/OS). Check the cache hit ratio's for the time periods in question. There could also be some z/os image to z/os image type interference. There *might* be some backend interference on the DMX4500, but this type of analysis would most likely require the assistance of EMC to identify the problem (if any). ESCON connections w/cache should provide 3-5 ms response time. Not sure about FICON/FIBRE CHANNEL. The RMF spreadsheet reporter has some very good information if you have it available. The DASD code mirrors some work Tom Berevtas had done prior to his retirement from IBM. I have taken his course and was quite impressed with his approach and the tuning results based on that approach. Performance Associates( http://www.perfassoc.com/) might also have some good info. HTH, <snip> We are running an EMC DMX4500 shared with the open system side. MVS has 9TB and the open side has 500TB. So they win. We have points in time where our production application (DB2 Stored Procedures with Native SQL) has slow responses. The DBAs are using RMF and TMON (DB2 and MVS) to isolate the problem. However, they see DFHSM and say thats the problem. I think I am seeing delays on the dasd the DB2 system uses in RMF. But I am not sure how to interpret the numbers. Is there a ROT that says if the delay rate is > ? then the dasd is poor performaing? </snip> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
