110 Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
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5.1.3.2
Log Select command (4Ch)
The Log Select command provides a means for an initiator to manage statistical information about the drive
operation. This information is logged within the drive and can be sent to the initiator in response to a Log
Sense command from the initiator. The Log Select command format is shown in Table 5.1.3.2-1. In the Data
Out phase following the command, the initiator sends zero or more pages of control parameters in the Log
Page Format of Table 5.1.3.2-3. These Log Pages contain parameters that command the drive to change
selected threshold, or cumulative values of any or all drive logs. Numbers in brackets [ ] refer to notes
following tables.
The following tables in section 5.1.3.2 apply for the Log Select command as indicators of functions that
command the drive to perform or enable for performance, control parameter bits the drive shall set/reset/
save, log counts that shall be kept, and etc. For the Log Sense command [1] these tables apply as indicators
of functions the drive reports back to the host that it is enabled to perform, control parameter bits that are set/
reset/saved, log counts that are being kept, and etc. Though the language of the descriptions is for the Log
Select case, the application to the Log Sense case should also be considered.
The drives represented by this Interface Manual do not support keeping independent sets of log parameters
(one set for each initiator in the system). If at some point log parameters are changed (by a Log Select
command) that affect initiators other than the initiator that sent the Log Select command, the drive generates
a unit attention condition for those other initiators, but not for the one that issued the Log Select command.
When the other initiators at a future time connect to the drive, the first command attempted would not execute
and a check condition status would be issued by the drive. A Request Sense command would normally follow
and a unit attention condition sense code be returned to these other initiators with an additional sense code
of LOG PARAMETERS CHANGED. (one by one as they connect to the drive) See Section 4.6, Unit Attention
Condition.
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[1] Section 5.1.3.3 describes the Log Sense command, but the tables of this section that apply are not
repeated there.
