We have a number of TSM server instances running under Linux on
two mainframe systems. Neither system has z/VM installed; each
Linux instance runs in a separate LPAR. We have a z9 system with
two 5.5.4.0 TSM servers running under two Linux images. We have
ten FCP attached tape drives (a mixture of 3592J and TS1120
drives). We use a separate device (in the IOCP sense of a device)
for each drive.

We recently installed a z10 system with two 6.2.2.0 TSM server
instances running under a single Linux image. We have no trouble
sharing tape drives between the z10 Linux image and one of the
z9 Linux images. We have, for example, run tests with one of
the 6.2 instances acting as a library manager, the other 6.2
instance acting as a library manager client, and our 5.5.4.0
test server acting as a second library manager client.

Sharing tape drives between the two z9 LPARs has so far been
far more laborious and disruptive. When we have needed a
tape drive on the test server we have historically removed
the device (in the IOCP sense) from one LPAR and added it to
the other LPAR. We have to quiesce all tape activity before
doing this; I/O operations on other tape drives will
frequently hang if a device is removed or added.

Is it possible to make tape drive sharing between two LPARs
on the same system work as smoothly as drive sharing
between LPARs on different systems?