IBM TS4300 User Manual page 132

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Cartridge Slot SCSI element address
SCSI element addresses are separately assigned to mail slots (import export elements) and storage slots
(storage elements) for each library partition. This assignment can be changed by SCSI initiators using
the element assignment mode page. SCSI element addresses are counted in the same order as the Slot
PNUM. Slot PNUM and element addresses may be not contiguous if mail slots are enabled in the middle of
a partition.
Drive Numbering
Drive numbering uses all 3 numbering systems to identify drives inside the library: Logical ID, Physical
Number, and SCSI Element address.
Drive Logical ID
Drives are numbered from bottom to top, starting with 1. Only drives which are present in the stack are
counted. Adding or removing drives will cause re-numbering of drives.
Drive Physical Number (PNUM)
Drive PNUMs start with the lowest possible bay (drive sled connector) in a full module stack and ending at
the highest possible bay. Installed drives will have the PNUM of the drive bay in which they are installed.
Full High tape drives take up two bays but they are numbered using the lower bay where they plug into
the library. The PNUMN of the upper bay behind a full high drive will never be assigned to a drive. Since
21U and 48U Libraries have different full module stack heights, the PNUMs will be assigned differently.
The lowest drive bay of the base module in a 48U library will always have PNUM 25. The lowest drive
bay of the base module in a 21U library will always have PNUM 10. Drives above the base module will be
numbered higher. Drives below the base module will be numbered lower. Assignment of WWI's and serial
number spoofing is based on the physical drive number.
Drive SCSI element address
SCSI element addresses are separately assigned for each library partition and can be changed by SCSI
initiators using the element assignment mode page. SCSI element addresses are counted in the same
order as the Drive IDs. There are no gaps permitted in SCSI element addresses. Adding or removing drives
may cause re-numbering of the element addresses.
Drive re-numbering considerations:
Drive logical IDs for user interfaces are automatically updated each time when a drive gets added or
removed. The drive re-enumerations shall also take place, when the admin, service or secret user does a
"Reset the List of Known Drives and Modules".
SCSI element addresses will never change automatically when adding or removing drives. Drives which
are disabled or temporary removed will still be reported to the SCSI host but with the access bit not
set. Drives added to the sled connector for the very first time are not assigned to any partition and
have therefore no SCSI element address. They can however be used for move operations via RMI or
OCP. Updating SCSI element addresses of existing partitions or adding new drives to a partition requires
running a partitioning wizard (basic or expert).
Numbering Diagrams
The chart below shows the Logical IDs, PNUMs and Element Addresses for a full 21U library.
100 IBM TS4300 Tape Library Machine Type 3555: User's Guide