Sun Microsystems StorageTek Modular Library System SL500 - Manual (Page 183)

Partitions and CAPs
96116 • Revision: KA Chapter 6 Library Partitioning 151
Partitions and CAPs
The cells within each CAP can be allocated or unallocated individually to partitions.
This allows for the following possible CAP configurations:
■
Common CAP
■
Split CAP
Note – Split CAPs are available to the SL500 only.
Common CAP
In a common, or unassigned, CAP, all cells in the CAP are left unallocated and can be
used by any partition that does not have any CAP cells allocated to it. CAP cells are
common by default—any CAP cells that are not explicitly allocated to a partition are
treated as common.
A common CAP is a shared library resource. Each host must select a common CAP to
use it and must release the CAP when done, to make it available to other hosts. No
other host can access the CAP until the first host has completed the operation and
released the CAP. For additional details, see “CAP Operations” on page 151 .
Split CAP
In a split CAP, the cells in the CAP are allocated to one or more partitions. Each
individual CAP cell can be allocated to one partition only. Cells in a split CAP can be
allocated in any of the following ways:
■
All cells can be allocated to one partition.
■
All cells can be distributed among multiple partitions. For example, in an eight-cell
CAP, two cells could be allocated to Partition 1, one cell to Partition 2, and the
remaining cells to Partition 3.
■
Some cells can be allocated to one partition and the remainder left unallocated, or
common. For example, in an eight-cell CAP, five cells could be allocated to
Partition 3, and the remaining cells left common.
When configuring a split CAP, you must plan carefully for anticipated CAP usage. A
partition with allocated CAP cells can use the cells allocated to it only. It cannot use
CAP cells allocated to other partitions, nor can it use common CAP cells.
CAP Operations
In a partitioned library, it is recommended that you assign partitions to the CAP Open
button on the library control panel prior to pressing the button to open the CAPs.