User Manual

SCSI Commands Reference Manual, Rev. J 368
www.seagate.com Parameters for direct access devices
The parameter value in the accumulated start-stop cycles log parameter (parameter code 0004h) shall contain a four-byte binary
value that indicates how many stop-start cycles the SCSI target device has detected since its date of manufacture. The
accumulated start-stop cycles parameter shall not be saveable by the application client using the LOG SELECT command (i.e.,
the log parameter DS bit shall be set to one). The time at which the count is incremented during a start-stop cycle is vendor
specific. For rotating magnetic storage devices, a single start-stop cycle is defined as an operational cycle that begins with the
disk spindle at rest, continues while the disk accelerates to its normal operational rotational rate, continues during the entire
period the disk is rotating, continues as the disk decelerates toward a resting state, and ends when the disk is no longer rotating.
For devices without a spindle or with multiple spindles, the definition of a single start-stop cycle is vendor specific. The count is
incremented by one for each complete start-stop cycle. No comparison with the value of parameter 0003h shall be performed
by the device server.
The parameter value in the specified load-unload count over device lifetime log parameter (parameter code 0005h) shall contain
a four-byte binary value that indicates how many load-unload cycles may be performed over the lifetime of the SCSI target
device without degrading the SCSI target device's operation or reliability outside the limits specified by the manufacturer of the
SCSI target device. The specified load-unload count parameter shall not be saveable by the application client using the LOG
SELECT command (i.e., the log parameter DS bit shall be set to one). The time at which the count is incremented during a
specified load-unload count is vendor specific. For rotating magnetic storage devices, a single load-unload cycle is defined as an
operational cycle that begins with the disk spindle at rest, continues while the disk accelerates to its normal operational
rotational rate, continues during the entire period the disk is rotating, continues as the disk decelerates toward a resting state,
and ends when the disk is no longer rotating. For devices without a spindle or with multiple spindles, the definition of a single
load-unload cycle is vendor specific. The count is incremented by one for each complete load-unload cycle. No comparison with
the value of parameter 0005h shall be performed by the device server.
The parameter value in the accumulated load-unload count over device lifetime log parameter (parameter code 0006h) shall
contain a four-byte binary value that indicates the SCSI target device has detected since its date of manufacture. This saturating
counter is incremented by one for each complete cycle. The time in the cycle at which the counter is incremented is vendor
specific.
For rotating magnetic storage devices (see SBC-4), a single load-unload cycle is defined as an operational cycle that:
a) begins with the heads unloaded from the medium;
b) continues while the heads are loaded onto the spinning medium; and
c) ends when the heads are unloaded from the medium.
The Accumulated Load-Unload Cycles log parameter is not applicable to rotating magnetic storage devices without unloadable
heads.
The device server shall not compare the contents of the ACCUMULATED LOAD-UNLOAD CYCLES field to contents of the
SPECIFIED LOAD-UNLOAD COUNT OVER DEVICE LIFETIME field.
DS bit, SPF bit, PAGE CODE field, SUBPAGE CODE and PAGE LENGTH field
The DS bit, SPF bit, PAGE CODE field, SUBPAGE CODE and PAGE LENGTH field are described in 5.2.2.