Elliott, Robert (Server Storage) elliott at
Thu Feb 10 07:21:26 PST 2005

* From the T10 Reflector (t10 at, posted by:
* "Elliott, Robert (Server Storage)" <elliott at>
> * From the T10 Reflector (t10 at, posted by:
> * <sungwon_ha at>
> I have a question regarding Serial Attached SCSI - 
> 1.1(SAS-1.1) draft. 
> In the draft, HARD_RESET primitive is defined and actions 
> triggered by arrival of the HARD_RESET primitive are well-defined. 
> My question is on what conditions, HARD_RESET primitive is 
> sent. One condition can be the arrival of SMP PHY CONTROL 
> request which specifies HARD RESET PHY OPERATION. Other than 
> that condition, the draft does not mention when and why 
> HARD_RESET primitive is sent. 
> Thanks.

Expanders only send it when instructed with SMP (sent by initiator as
requested by software).  Initiators only send it when requested by

It can be used whenever SCSI software wants to invoke a SCSI "hard
reset" condition (as defined in SAM-3) in an SSP target device.

It can also be used when ATA software wants to clear an STP affiliation
held by another STP initiator (e.g. it keeps getting OPEN_REJECT (STP
RESOURCES BUSY), and the STP initiator port holding the affiliation (as
reported by REPORT PHY SATA) is no longer in the SAS domain (as
determined by the discover process).

Rob Elliott, elliott at
Hewlett-Packard Industry Standard Server Storage Advanced Technology
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at

More information about the T10 mailing list