OS390_Cache_Read_HitPct_Warn

OS390_Cache_Read_HitPct_Warn monitors the percent of successful I/O requests to read data from the cache and issues a Warning if the percentage is between 51% and 70% inclusive.

The formula is:

IF VALUE DASD_MVS_Devices.Cache_Read_Hit_Percent LE 70 AND VALUE DASD_MVS_Devices.Cache_Read_Hit_Percent GT 50

If this situation raises, determine whether dataset placement should be adjusted (I/O tuning). If goals are being missed, tuning may be required. If no goals are being missed, the threshold may need to be adjusted.