IBM System Storage TS3500, Introduction And Planning Manual

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Instead, the library automatically moves the cartridges and places them into
virtual I/O slots until they are ready to be processed later as one composite set
of inserted cartridges.
v
In a typical export scenario without virtual I/O slots, the system administrator
may need to export a large number of cartridges from the library. However, after
the I/O station is filled, he must wait for the operator to physically remove
cartridges from the entire I/O station before he can issue another export
command. This operation can be inconvenient. If the library is enabled with
virtual I/O slots, the administrator does not have to wait to issue all export
commands (up to 255 export commands can be issued at the same time for each
logical library) and the operator can remove cartridges from the I/O stations as
soon as the accessor automatically moves them from the storage slots.
With virtual I/O slots enabled, the library has various mechanisms for selecting
the best storage slot location for each inserted cartridge, as well as the best
accessor and I/O station for each ejected cartridge. These mechanisms vary
depending on the configuration of your library.
For ejects with virtual I/O slots enabled and I/O stations in both preferred zones
of a dual accessor library, the library selects the accessor and I/O stations that are
in the same preferred zone as the physical slot of the cartridge to be ejected, but
will maintain First In, First Out (FIFO) order for each zone. For ejects with virtual
I/O slots enabled and I/O stations in only one zone of a dual accessor library, the
library selects the accessor in that preferred zone and maintains FIFO order.
For more information, see “Cartridge assignment policy” and “Insert notification
setting” on page 49.
For detailed information about import and export performance in libraries with
virtual I/O slots enabled, refer to “Import and export performance with virtual
I/O slots” on page 86.
Cartridge assignment policy
This section describes the cartridge assignment policy for assigning cartridges to
specific logical libraries.
You identify a cartridge by affixing a label to it that bears a volume serial
(VOLSER) number. The cartridge assignment policy allows you to specify one or
more
ranges of VOLSERs for logical libraries. For example, you can create a
cartridge assignment policy of 36 cartridge VOLSERs that range from 000764 to
000800 for a specific logical library. Note that VOLSERs in ranges do not include
the media-type indicator, such as L2, L3, JA, and so forth.
When you insert a cartridge into the library and its VOLSER is within a range, the
cartridge assignment policy assigns the cartridge to its logical library. The cartridge
must be of the same media type as that logical library. For example, if you create
for Logical Library 1 (a library of Ultrium drives) a cartridge assignment policy of
VOLSERs that range from ABC000 to ABC999 then you insert a cartridge with
VOLSER ABC123, the library recognizes that VOLSER as belonging to the range
and assigns it to Logical Library 1, provided that the cartridge is an Ultrium tape
cartridge (and not a different media type, such as a 3592 tape cartridge).
When an unassigned cartridge is present in the I/O station, the library reads its
VOLSER label and automatically assigns it to the logical library that is specified in
the range of VOLSERs which was previously selected by the system administrator
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IBM System Storage TS3500 Tape Library with ALMS: Introduction and Planning Guide