Explanation: DELETEBYAGE, DELETEIFBACKEDUP,
and MIGRATE are mutually exclusive, optional subparameters of the
PRIMARY parameter specifying the space management type on the primary
volume.
- DELETEBYAGE (days)
- specifies that cataloged and uncataloged data sets that reside
on a primary volume are scratched if they have been inactive for a
specified number of days and the current expiration date has been
reached. If you specify this subparameter, a current backup version
of the data sets on the primary volume is not required. For days,
if you are in a single-DFSMShsm-host environment, substitute a number
from 1 to 999. In a multiple-DFSMShsm-host environment, you can specify
a number from 2 to 999. For example, if you specify days as
20, DFSMShsm scratches those data sets on a primary volume that have
been inactive for at least 20 days.
- DELETEIFBACKEDUP(days)
- specifies that the data sets on a primary volume can be scratched
if they have been inactive for a specified number of days and if the
data sets on the primary volume have current backup versions. For days, in a single-DFSMShsm-host environment, substitute a decimal
number from 1 to 999. In a multiple-DFSMShsm-host environment, you
can specify a decimal number from 2 to 999. For example, if you specify days as 30, DFSMShsm scratches those data sets that have been
inactive for 30 days and that have a current backup version.
- MIGRATE
- specifies that the data sets that reside on a primary volume
are migrated according to the number of days they have been inactive.
- MIGRATE(days)
- depends on whether you have defined valid thresholds of occupancy.
If you do not define thresholds of occupancy, migration causes all
data sets not accessed in the last days days to migrate.
If you define thresholds of occupancy, DFSMShsm migrates data sets
until the low threshold of occupancy is met or until all the data
sets inactive for the number of days specified have migrated.
For days, you can specify a decimal number from 0 to 999.
For example, if days is specified as 25, DFSMShsm migrates
those data sets on the primary volume that have been inactive for
at least 25 days until the low threshold of occupancy is met (if you
have defined thresholds of occupancy) or until all data sets inactive
for 25 days or longer have been migrated.
Defaults: If you are adding a primary volume
to DFSMShsm, the default is MIGRATE. If you are changing the attributes
of a volume and do not respecify a subparameter, the space management
technique does not change.
Note: - If you do not specify days with the MIGRATE subparameter,
or you specify 0, or you specify 1 in a multiple-DFSMShsm-host environment
when USERDATASETSERIALIZATION is not specified, the number of days
the data set can remain inactive before it is allowed to migrate is
the value specified with the DAYS parameter of the SETSYS command.
- In a multiple-DFSMShsm-host environment, you can add the same
volume to different DFSMShsm hosts. When you do that, the space management
technique for that volume must be the same in all DFSMShsm hosts,
or the last one specified with the ADDVOL command is the one that
is in effect.
- DFSMShsm automatically recalls a data set to a primary volume
whose space management technique is MIGRATE even if the data set migrated
from a volume whose type of space management is DELETEBYAGE or DELETEIFBACKEDUP.
This is true even if you specified SETSYS RECALL(LIKE).