You can group together tape devices and define them as one group
to the system. For instance, a group of 3490 tape drives in the same
room can be grouped together and defined as 3490GRP. These tape device
groups are known as
esoterics. Once an esoteric is specified
on the SETOAM statement for a group, you need to ensure the existence
of that esoteric while an OAM tape exists that specifies that esoteric
in the TAPEUNITNAME field of the OAM tape volume (TAPEVOL) table.
Attention: Do not change the contents
of that esoteric to introduce incompatible tape device types. Should
the esoteric name be deleted or changed, the volumes associated with
the esoteric name cannot be allocated. Because the TAPEUNITNAME cannot
be resolved, the tape that is required for the request is not mounted
and the allocation request fails.
For scratch allocations for an ATLDS or MTL, the esoteric TAPEUNITNAME
associated with a storage group is overridden with the exact device
type for the device that is allocated for the MVS scratch tape mount.