Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.10.9 Mode Page 0A (Control Mode Page Parameters)Table 154:Page 0A (Control Mode Page Parameters)
Following are parameter options for Page 0A.
•Queue algorithm modifier specifies restrictions on the algorithm used for reordering commands that are tagged with the
SIMPLE message.
0h : Restricted reordering. The Target shall reorder the actual execution sequence of the queued commands from each
Initiator such that data integrity is maintained for that Initiator.
1h : Unrestricted reordering allowed. The Target may reorder the actual execution sequence of the queued commands
in any manner it selects. Any data integrity exposures related to command sequence order are explicitly handled by
the Initiator through the selection of appropriate commands and queue tag messages.
2h-7h : RESERVED.
8 : Command reordering is disabled
9-Fh : RESERVED
•QErr (Queue Error Management) The queue error management (QERR) field specifies how the device server shall han-
dle blocked tasks when another task receives a Check Condition status.
Byte Bit Default
76 5 4 3 2 1 0
0 PS 0 Page Code = 0Ah 8Ah
1 Page Length = 0Ah 0Ah
2 TST=0 TMFonly=0 RSVD=0 D_Sense=0 GLTSD=0 RLEC=0 00h
3 Queue Algorithm Modifier Rsvd=0 QErr DQue 00h
4 RSVD=0 RAC=0 UA_INTLCK_CTRL=0 SWP=0 Obsolete 00h
5 ATO TAS=0 Reserved=0 00h
6-7 Obsolete=0 00h
8-9 (MSB) Busy Timeout Period
(LSB)
00h
10-11 (MSB) Extended Self-test Routine
Completion Time (LSB)
XXh
QERR
value Description
00b
Specifies that all tasks from all Initiators are blocked from execution when a Contintent
Alligience (CA condition) is pending. Those blocked tasks are allowed to resume execution
in a normal fashion after the CA condition is cleared.
01b
Specifies that all tasks from all Initiators are aborted when the Target returns Check Con-
dition status. A unit attention condition will be generated for each Initiator that had com-
mands in the queue except for the Initiator that received the Check Condition status. The
sense key will be set to Unit Attention and the additional sense code will be set to Commands
Cleared by Another Initiator.