After you identify the filters to intercept the allocations and redirect them to DASD, determine the proper management class attributes, such as residency time on primary and migration level 1 storage. Consider the amount of space required to store the data set on primary or migration level 1 storage versus the number of mounts required to recall the data. The volume mount analyzer produces a report ranking all of the management classes by number of migration level 2 mounts, number of recalls, and additional tracks needed for the migration and recall activity for that management class.

The Management Class Report is sorted in descending order by L2-MOUNTS, RECALLS, and TOT TRKS. The most important value to keep low is the L2-MOUNTS, because it represents specific mounts. All other tape mount management mounts are scratch mounts. When you select a management class, you should rerun the Estimate Report with that management class.

The following control statements generate a Management Class Report for all data sets created by PGM=IDCAMS, but not those on 3420 tapes:

PGM(INC(IDCAMS))
UNIT(EXC(3420))
REP(MC)

Table 1 shows the five top-ranked management classes for the sample installation's tape mount management data sets generated by IDCAMS.