User's Guide

Chapter 3 Emulated DLT7000 SCSI Commands
Read Block Limits (05h)
Quantum DX-Series Software Interface Guide 233
The Granularity field is described in the table below.
Table 182 READ
BLOCK LIMITS Data -
Field Descriptions
Field Name Description
Granularity
(SCSI-3
Only)
This field indicates the supported block size granularity. The DLT7000 tape
drive supports all block sizes n such that n minus the minimum block length
limit is a multiple of 2
x
(where
x
is the value in the Granularity bits), and n is
greater than or equal to the Minimum Block Length Limit and less than or equal
to the Maximum Block Size Limit. For the DLT7000 system, the content of the
Granularity field is 1 (since block sizes must be a multiple of 2; 2
1
= 2).
For backward compatibility, the DLT7000 will process requests that do not
meet Granularity criteria, except for Odd-byte Multiple Block Fixed Block
WRITE commands when connected to a Wide (16-bit) SCSI bus.
Maximum
Block
Length
The value in this field indicates the maximum block size. The tape drive
supports a maximum block length of 16,777,214 (16 MB-2) for 10, 20, or 35 GB
format. A maximum block length of 256 K bytes is supported for 2.6 GB or 6.0
GB formats.
Minimum
Block
Length
The value in this field indicates the minimum block size. The tape drive
supports a minimum block length of 2 bytes.