AIX equivalent to Windows "snapshotcachelocation" option when using TSM image backups on AIX clients

We are currently running TSM image backups, (e.g. dsmc image backup
/disk01 -snapshotcachesize=10), but this sometimes fails because of
lack of space available in the Volume Group.

The problem is that when the backup runs it creates a new temporary
cache LV/filesystem in the same VG, which in this case will be 10% of
the size of the filesystem it is backing up. This temporary filesystem
uniquely named /tsm############ (prefixed tsm followed by 12 digits)
is only created/deleted during the backup and therefore the backup
fails if there is insufficient space to create it.

We would like an option added that allows us to predefine this cache area/FS, thus
reserving the space. Then when the backup is initiated, instruct it to
use this predefined FS instead.

It would appear in Windows that there is already an option to do this -
"snapshotcachelocation". Though the same option isn't available for AIX.

Without this option we are unable to reserve/pre-allocate the space, to stop
the 10% of space being accidently used to extend other filesystems. Which then causes the backups to fail.

Many thanks
Regards
Ian.