Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
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17.4.2
Hard Reset
A Hard Reset sequence on a port will not affect the other port, but the outstanding commands on the other port will
be aborted due to the LUN reset associated with the Hard Reset. The effect of a Hard Reset will be similar to a
Power on Reset, and will result in the re-initialization of all drive resources. The first command issued from every
initiator on the port that received the Hard Reset will result in a CHECK CONDITION with a sense key of UNIT
ATTENTION and an additional sense code of SCSI BUS RESET OCCURRED. The first command issued from
every initiator on the other port will result in a CHECK CONDITION and an additional sense code of BUS DEVICE
RESET OCCURRED.
A Hard Reset sequence will never be issued by the drive. A link reset will be initiated by the drive on the affected port
upon completion of Hard Reset processing.
17.4.3
SAS OOB (Out of Band)
Out of Band (OOB) signals are low-speed signal patterns detected by the PHY that do not appear in normal data
streams. They consist of defined amounts of idle time followed by defined amounts of burst time. During the idle
time, D.C. idle is transmitted. During the burst time, ALIGN (0) primitives are transmitted repeatedly. The signals are
differentiated by the length of idle time between the burst times.
As a SAS compliant device, the drive uses three OOB signals: COMINIT/COMRESET and COMWAKE and
COMSAS.OOB operations are beyond the scope of this specification. Please refer to the ANSI SPL-3 specification
for more details.
The drive will initiate OOB by sending COMINITs, under the following conditions:
- POR
- Loss of sync
- Identify timeout