SAS Wide link question

Wed Dec 11 16:18:34 PST 2002

* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert (Server Storage)" <Elliott at hp.com>
*
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If the target port is wide (i.e. it has more than one phy, advertising
the same SAS address), it may request a connection using any phy in the
wide port.  It doesn't have to remember the phy through which the
command arrived.
=20
Similarly, a wide initiator port may request a connection to a target
using a different phy than it has used previously.
=20
Expanders are also free to choose any link in a wide link as they route
connection requests through the domain.
=20
A wide initiator port should not ask for more than one connection at a
time to the same target port unless it knows the target port is also
wide (otherwise, all but one of its requests will lose arbitration to
the winner).
--=20
Rob Elliott, elliott at hp.com=20
Hewlett-Packard Industry Standard Server Storage Advanced Technology=20
https://ecardfile.com/id/RobElliott
<https://ecardfile.com/id/RobElliott> =20

-----Original Message-----
From: Kevin_Marks at Dell.com [mailto:Kevin_Marks at Dell.com]=20
Sent: Tuesday, December 10, 2002 1:20 PM
To: t10 at t10.org
Subject: SAS Wide link question

With an initiator and target in a SAS domain having a wide link
configuration, on a reconnect does the target for example have to
maintain allegiance to the original path (phy) when reconnecting or can
arbitrate for any path back to the initiator.

=20

Thanks

=20

Kevin

=20

Kevin Marks ( Kevin_Marks at Dell.com <mailto:Kevin_Marks at Dell.com>  )
=20

=20

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Message @page Section1 {size: 8.5in 11.0in; margin: 1.0in 1.25in 1.0in = 1.25in; } P.MsoNormal { 	FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman" } LI.MsoNormal { 	FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman" } DIV.MsoNormal { 	FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman" } A:link { 	COLOR: blue; TEXT-DECORATION: underline } SPAN.MsoHyperlink { 	COLOR: blue; TEXT-DECORATION: underline } A:visited { 	COLOR: purple; TEXT-DECORATION: underline } SPAN.MsoHyperlinkFollowed { 	COLOR: purple; TEXT-DECORATION: underline } SPAN.EmailStyle17 { 	COLOR: windowtext; FONT-FAMILY: Arial } DIV.Section1 { 	page: Section1 } If the=20 target port is wide (i.e. it has more than one phy, advertising the = same SAS=20 address), it may request a connection using any phy in the wide = port.  It=20 doesn't have to remember the phy through which the command=20 arrived.

 Similarly, a wide initiator port may request a connection to a = target=20 using a different phy than it has used previously.

 Expanders are also free to choose any link in a wide link as = they route=20 connection requests through the domain.

 A wide=20 initiator port should not ask for more than one connection at a time to = the same=20 target port unless it knows the target port is also wide (otherwise, = all but one=20 of its requests will lose arbitration to the = winner).
 -- = 
Rob Elliott, = elliott at hp.com=20 
Hewlett-Packard = Industry Standard=20 Server Storage Advanced Technology 
https://ecardfile.com/id/Ro= bElliott=20 

-----Original Message-----
From:=20 Kevin_Marks at Dell.com [mailto:Kevin_Marks at Dell.com] 
Sent: = Tuesday,=20 December 10, 2002 1:20 PM
To: = t10 at t10.org
Subject: SAS=20 Wide link question

 With an initiator and = target in a=20 SAS domain having a wide link configuration, on a reconnect does the = target=20 for example have to maintain allegiance to the original path (phy) = when=20 reconnecting or can arbitrate for any path back to the=20 initiator. Thanks= Kevin Kevin Marks ( Kevin_Marks at Dell.com=20 )