Here are some tips you might find helpful when using DFSMShsm with the 3592 Model E05 tape drive.
SETSYS UUT(3592E05:3592E05 3590H:3590H)
SETSYS BACKUP(TAPE(3592E05))
Consider performance segmentation as a compromise solution. Performance segmentation increases the performance of data sets in the first twenty percent of the tape's capacity, but also uses the remaining capacity as a slower access segment. Average performance for the tape is increased at the expense of losing a percentage of the MEDIA5 or MEDIA9 overall tape capacity. (You cannot determine which data sets reside in which segment.)
DFSMShsm recycle processing of 3592 Model E05 tapes can take significantly longer than with smaller tapes because the amount of data moved at the same RECYCLEPERCENT can be much larger. Besides moving more data, the likelihood of a tape takeaway for recall processing increases with the number of data sets still remaining on the tape.
One option for controlling overall recycle run time is the LIMIT(nnnn) parameter of recycle. Recycle returns no more than the specified number of tapes to scratch during the current recycle run. Because recycle sorts the tapes based on the amount of valid data still on each volume, the tapes recycled require the least processing time.
Another option to consider is decreasing the ML2RECYCLEPERCENT parameter, the RECYCLEPERCENT parameter, or both. Assume, for example, that your installation uses MEDIA7 tape for ML2 and MEDIA5 tape for backup. If the EFMT1 format is used and you would like no more than 6 GB of data to be moved when an ML2 tape is recycled, set ML2RECYCLEPERCENT(10) because a MEDIA7 tape can hold 60 GB of data in EFMT1. If your installation uses full capacity for backup tapes and you want no more than 6 GB of data to be moved when a backup tape is recycled, set RECYCLEPERCENT(2) because a MEDIA5 tape can hold 300 GB of data in EFMT1. These examples assume that the ML2 and backup tapes in the installation are filled to capacity because the calculations are based upon the average fullness of marked full tapes on your system (the reuse capacity.)
To determine how much data your current recycle threshold implies, use the reuse capacity associated with the tapes. The current recycle threshold percent multiplied by the reuse capacity gives the maximum amount of data on any of the tapes when they are recycled.
While lowering the recycle threshold reduces recycle processing time and decreases the number of times each tape must be recycled, it may also increase the overall number of tapes needed in your installation. Also, if you have a mix of ML2 or backup tape capacities in need of recycle processing, you may want to recycle tapes with the RANGE parameter and use the appropriate recycle threshold for the tape capacities in the range.
In an SMS tape environment, and optionally in a non-SMS tape environment, the SMS data class construct can be used to select WORM tapes for ABACKUP processing. The output data set prefix specified in the aggregate group definition can be used by the ACS routines to select a WORM data class. Set up the ACS routine and the output data set name to uniquely identify the ABARS output files that must go to WORM tape.
In a non-SMS tape environment, the default is to allow tape pooling to determine if ABARS data sets go to WORM or R/W media. Optionally, if the DEVSUP parameter ENFORCE_DC_MEDIA=ALLMEDIATY or ENFORCE_DC_MEDIA=MEDIA5PLUS is used, the data class must request the appropriate media type for it to be successfully mounted.