OS390_Cache_Write_HitPct_Warn

OS390_Cache_Write_HitPct_Warn monitors the percent of successful I/O requests to write temporary data to the cache and issues a Warning alert if the percentage is between 51% and 70% inclusive.

The formula is:

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

If this situation is raised, determine whether any address spaces that have this device number allocated are in service classes that are missing their goals. If goals are being missed, dataset placement (I/O tuning) may be required.