NTAC:3NS-20 We had a situation with a bad cable that resulted in a huge performance impact due to the default way that z/OS (we are at 1.13) handles error recovery on Ficon paths. The symptoms were many (thousands) of IOS050I messages in the task's joblog, followed by an IOS450E message, which took the path offline to a single device. This was happening for every device (around 3000) that the affected path was attached to. As soon as I saw the messages I configured the CHPID offline and the problem stopped. We have put in automation that will immediately configure a CHPID offline as soon as a single IOS450E message is detected, and now I am experimenting with RECOVERY options. IBM recommended to set RECOVERY,PATH_SCOPE=CU, set the PATH_INTERVAL to 1 and leave PATH_THRESHOLD=10, and adjust from there.
Due to the paperwork involved with making any change in our environment, I would like to implement this with a minimum of 'adjustment'. Does anyone have any recommendations? We are running on z13s, 16G Ficon through Brokade switches to IBM DS88xx DASD. Thanks, Jim ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
