Automated Media Pools white paper for ESL G3 (QN998-96026, June 2011)

Configuring for flexibility
Two partitions, partition 1 and partition 2, are carved
out of the tape library as demonstrated in figure 1.
These partitions appear as physical tape libraries
on the SAN. For the purpose of this example, we
will assume that partitions 1 and 2 each contain
24 storage slots. However, in practice they will also
contain tape drives and perhaps mail slots. Along
with partitions 1 and 2, the administrator has set up
an AMP partition of 96 slots. AMP partitions may
only contain storage slots, acting only as a media
backing store.
Any ISV applications on the SAN will only see the
two virtual libraries: Partition1 and Partition 2 with a
total of 120 slots in each partition (see figure 2).
Of these 120 slots, 24 will be “accessible”
within each partition, and the other 96 will be
“inaccessible”; the slots within the AMP are not
available to the SAN. Each virtual partition will add
the total amount of slots in the AMP to the available
slot count it reports to the ISV software. In other
words, the ISV believes each partition to be larger
than it is in reality to provide head-room for growth.
In this case, we can assume that the 24 slots in
Partition 1 are sufficient to meet the exclusive
storage requirements for customer A, while the 24
slots in Partition 2 are sufficient for customer B. The
remaining 96 media slots within the AMP currently
remain unallocated.
Figure 2: Logical view of the
allocation of partitions – as seen
by an ISV application
Partition 1 (120 slots) 24 accessible
ISV View
AMP = 96 slots
Partition 2 (120 slots) 24 accessible