User Manual

SCSI Commands Reference Manual, Rev. J 135
www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)
The device server shall check the protection information read from the medium before returning status for the command as
described in table 96.
Table 96 Protection information checking for READ (6)
Logical unit
formatted with
protection
information
Shall device server
transmit protection
information?
Field in protection
information [e]
Extended INQUIRY
Data VPD page bit
value [d]
If check fails [b]
[c]
,
additional sense code
Yes No LOGICAL BLOCK
GUARD
GRD_CHK = 1
LOGICAL BLOCK GUARD CHECK FAILED
GRD_CHK = 0
No check performed
LOGICAL BLOCK
APPLICATION TAG
APP_CHK = 1
[a]
LOGICAL BLOCK APPLICATION TAG
CHECK FAILED
APP_CHK = 0
No check performed
LOGICAL BLOCK REF-
ERENCE TAG
REF_CHK = 1
[f] [g]
LOGICAL BLOCK REFERENCE TAG CHECK
FAILED
REF_CHK = 0
No check performed
No
No protection information available to check
[a] The device server checks the logical block application tag only if it has knowledge of the contents of the LOGICAL BLOCK
APPLICATION TAG field. The method for acquiring this knowledge is not defined by this manual.
[b] If an error is reported, the sense key shall be set to ABORTED COMMAND.
[c] If multiple errors occur, the selection of which error to report is not defined by this manual.
[d] See the Extended INQUIRY Data VPD page (see 5.4.9) for the definitions of the GRD_CHK bit, APP_CHK bit,
and REF_CHK bit.
[e] If the device server detects a:
a) LOGICAL BLOCK APPLICATION TAG field set to FFFFh and type 1 protection (see
SBC-4)
or type 2 protection (see
SBC-4) is enabled;
or
b) LOGICAL BLOCK APPLICATION TAG field set to FFFFh, LOGICAL BLOCK REFERENCE TAG
field set to FFFF FFFFh, and type 3 protection (see
SBC-4) is enabled,
then the device server shall not check any protection information in the associated logical block.
[f] If type 1 protection is enabled, the device server checks the logical block reference tag by comparing it to the lower 4 bytes
of the LBA associated with the logical block.
[g] If type 2 protection or type 3 protection is enabled, the device server checks the logical block reference tag only if it has
knowledge of the contents of the LOGICAL BLOCK REFERENCE TAG field. The method for acquiring this knowledge is not
defined by this manual.