CA Dynam for VSE User Guide

Modifying Logical Unit Assignments (LUBS)
COMLUB Option Record Processing
If you specify a range of LUB entries with the COMLUB option record, then CA
Dynam/D checks each LUB entry specified and uses the first free LUB in the
range. Multiple LUB ranges can be specified for each active partition.
LUB Assignments
If all of the LUB entries specified are in use and none are assigned to the
desired disk address, an error message NO FREE LUBS AVAILABLE appears
and the job is canceled. However, if one of the LUB entries is available or is
already assigned to the correct disk address, then the original assignment is
overridden.
If the COMLUB option record is not available, CA Dynam/D will scan all LUB
entries for the partition (in descending order) to find either an available LUB or
a LUB which is assigned to the desired disk address. If such a LUB is found, it
is the one used. Otherwise, an error message appears and the job is canceled.
Dynamic LUB allocation ensures that an existing logical unit assignment is
generally never modified. Thus, the danger of cross-assignment of files
assigned to the wrong disk volume is eliminated.
Note: Whenever CA Dynam/D must change an existing assignment, the
message CADD037A ASSIGNMENT OVERRIDE appears on the operator's
console (For more information, see message explanation.). The possible
actions to be taken in response to this message are:
To
Cancel the job
Specify the nnn assignment to use instead
Allow dynamic LUB allocation to find a new logical unit
Change the assignment
Type
CANCEL
SYSnnn
COMLUB
IGNORE
4–28 User Guide