HP Q153090901 0Bh, SET CAPACITY

SET CAPACITY 0Bh

This provides a means of changing the logical length of the currently-loaded media. The primary use envisaged is for testing purposes, although it may also be used in other circumstances where a shortened tape may be beneficial.

Note that all data currently on the media will be lost following successful execution of this command. The command is only accepted when the media is positioned at Beginning of Media (BOM).

With WORM cartridges, the command is only accepted and executed if the cartridge has not been initialized, that is, it has never been written to. Otherwise the cartridge is rejected with CHECK CONDITION, sense key of Data Protect and additional sense of 300Ch (WORM media— overwrite attempted). TapeAlert flags 3Ch (WORM media—overwrite attempted) and 09h (write- protect) are set.

Pre-execution checks:

Illegal Field	Reservation	Deferred Error
Unit Attention	Media Access	Media Write

Command descriptor block:

	7	6	5	4		3	2	1	0
0				Operation	Code (0Bh)
1				Reserved (0)					Immed
2				Reserved (0)
3	(MSB)			Capacity Proportion Value
4									(LSB)
5				Control

CDB fields:

Immed	0	Status will not be returned until the SET CAPACITY operation has completed.
	1	Status will be returned as soon as the CDB has been parsed.
Capacity	The portion of the total volume capacity to be made available for use. The value

Proportion Value given here is the numerator of a fraction with a denominator of 65,535. The

resulting available capacity will be total volume capacity ⋅ capacity proportion value .

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65535

Note that the LTO-3 format enforces a minimum tape length. A value that would result in a tape length below this minimum will be silently rounded up to the minimum permitted length.

170 Commands