IBM B-Series, Maintenance Information

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Library Operation
This section describes the library modes of operation, operating procedures, and operator menus for
Models B01, B11, B02, B12, B21 and B22.
Library Modes of Operation
This section describes the library modes of operation, operating procedures, and operator menus for
Models B01, B11, B02, B12, B21 and B22.
The library processes cartridges either sequentially or non-sequentially under direction of the host. For
sequential processing, the library is capable of operating in either automatic or manual modes, selectable
at the operator panel. These two modes are identical except that following each unload operation in
manual mode, the operator must push a button to initiate the next load operation.
In order to process cartridges in a non-sequential manner, the library must be set to random mode at the
operator panel.
The mode selected by the operator is stored in non-volatile memory and becomes the default mode during
subsequent power-on cycles.
ADSM Note: it is recommended the Magstar MP be configured to operate in Random Mode in Base
Configuration. This allows ADSM to use the second drive for reclamation.
Random Mode
Random mode allows the Magstar MP to act as a self-contained library of up to 19 cartridges, controlled
entirely by SCSI hosts. In addition, access is provided to a 20th cartridge through the priority cell. The host
uses SCSI commands to a Medium Changer device to select a cartridge from a source element and move
it to its destination element. Control of the source and destination elements is left entirely to the host.
A request for an external cartridge to be mounted can be satisfied by inserting the cartridge into the
priority cell in the import position. The Magstar MP notifies hosts of the presence of a cartridge in the
priority cell, but the host must specifically address that cell to access the cartridge.
When the destination of a move is a magazine cell, the transport mechanism places the cartridge in the
cell in the import position for possible later re-use. However, if the destination is the priority cell, the
transport mechanism places the cartridge in the cell in the export position.
Because the library door must be closed while in random mode, the priority cell is used as an
import/export station to add or remove cartridges from the library without violating the integrity of the
magazine inventory. A host can cause cartridges from the priority cell to be moved to any empty magazine
cell or to a device. It can also cause cartridges from a magazine or a device to be moved to the priority
cell. Requests for external cartridges to be mounted can only be satisfied when magazine 1 (the rightmost
magazine) is present. Library inventory and control is entirely the responsibility of the hosts. If the library
door is opened while in random mode, the drive responds to the next command with a Unit Attention
condition.
LIBRARY
Library
LIBRARY-5