SAS STP: maintaining affiliations through SATA/SAS changes

Sheffield, Robert L robert.l.sheffield at
Wed Jan 29 17:33:32 PST 2003

* From the T10 Reflector (t10 at, posted by:
* "Sheffield, Robert L" <robert.l.sheffield at>
I think anytime an expander generates a CHANGE due to an event on a port, it should clear any active affiliations on that port. Does an expander-initiated link reset cause a CHANGE to be sent? I hope not. The intent was to provide a way for an STP initiator to reset a SATA device without clearing its own affiliation.

Sent from my BlackBerry Handheld.

-----Original Message-----
From: Hoglund, Tim <thoglund at>
To: 'Elliott, Robert (Server Storage)' <Elliott at>; t10 at <t10 at>
Sent: Wed Jan 29 15:24:11 2003
Subject: RE: SAS STP: maintaining affiliations through SATA/SAS changes

How about:
Expander initiated link reset sequence keeps affiliation.
Wire-initiated OOB clears affiliation (assume SATA drive won't initiate OOB after it's up and running)
In this manner initiators issuing link reset via SMP can keep affiliation.
If a SAS drive is plugged in then affiliation is cleared as it should be.
If a SATA drive is plugged in then affiliation is cleared, assume hot-plug event, initiators must resolve ownership.

Tim.Hoglund at 
719/533-7450 (Voice) 
719/533-7480 (Fax) 

-----Original Message-----
From: Elliott, Robert (Server Storage) [mailto:Elliott at]
Sent: Wednesday, January 29, 2003 3:14 PM
To: t10 at
Subject: SAS STP: maintaining affiliations through SATA/SAS changes

The current text in 9.3.2 indicates STP affiliations are maintained until expander power off, SMP PHY CONTROL requests to change them, or CLOSE (CLEAR AFFILIATION).

It specifically mentions that link reset sequences (e.g. from removing the SATA device) do not change affiliations. 

If a SATA device is pulled and a SAS port shows up in its place, do we want the expander to continue maintaining the affiliation?  It obviously should not not block OPENs headed to the SAS port.  If the SAS port is removed and a SATA device is put back, should the affiliation still be there?

Rob Elliott, elliott at 
Hewlett-Packard Industry Standard Server Storage Advanced Technology 

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