From: Bob.Nixon@emulex.com To: <Shawn.Authement@texmemsys.com>, <t10@t10.org> Date: Wed, 1 Oct 2008 14:34:32 -0700 Subject: RE: I_T nexus loss X-Message-Number: 9150 Formatted message: HTML-formatted message Hi, Shawn, sorry to be slow in responding, but as you pointed out, it's vague in the standads that apply (FCP-3/4 and FC-LS), and I ahd to struggle to find anything. In the end, I came to the same conclusion as Kevin Butt about intent. There is some hint in both standards that a PLOGI in the presense of an existing N_Port Login is traumatic: In FCP-4 table 7, the columns for PLOGI and PRLI are the same as the ones for LOGO and PRLO. In FC-LS concerning PLOGI, the third paragraph of subclause 6.3.2.1 requires treatment of new Sequences "as though a Logout had been performed". From the standpoint of FC-LS, this is essentially equivalent to an implicit logout, since FC-LS and FC-FS-3 specify no persistent behavior that is not either renegotiated by PLOGI or reflected in the collection of open Sequences. Concerning PRLI, FC-LS insists on the next to last paragraph on page 180 (printed numbering) that it does NOT imply Process Logout; however, the last paragraph suggests the iimpact is similar if Service Parameters are changed. FCP-3/4 would appear to override this, at least in part. You're right that some clarification would be nice. I suspect that FC-LS-2 needs to explicitly say that a PLOGI causes implicit logout of any existing N_Port Login with the same N_Port, and FCP-4 should say that PRLI causes I_T nexus loss if it changes existing FCP-4 Service Parameters. Others on this reflector may be able to make a better statement. Would you like to propose text for FCP-4 and/or FC-LS-2? Would you like me to? - bob nixon (secretary for FCP-4 and FC-LS-2) ________________________________ From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of Shawn Authement Sent: Wednesday, October 01, 2008 9:31 AM To: t10@t10.org Subject: Re: I_T nexus loss A big thank you to all who responded! I was just wondering if anyone may know where I can reference the situations which cause an implicit LOGO/PRLO, or maybe is this a better question to ask T11? FC-LS-2 section 6.4.4 seems to be vague on the issue, and doesn't mention this case. Thanks, -- Shawn Authement Sr. Software Engineer Texas Memory Systems, Inc. Shawn.Authement@texmemsys.com<mailto:Shawn.Authement@texmemsys.com> ph: +1.713.266.3200 Kevin D Butt wrote: Shawn, Yes, when an N_Port performs a PLOGI/PRLI it logs in again. This can be viewed as an implicit LOGO/PRLO and as stated in 4.11 of FCP-4 (http://www.t10.org/ftp/t10/drafts/fcp4/fcp4r01.pdf) this generates an I_T nexus loss notification. Regards, Kevin D. Butt SCSI & Fibre Channel Architect, Tape Firmware MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744 Tel: 520-799-2869 / 520-799-5280 Fax: 520-799-2723 (T/L:321) Email address: kdbutt@us.ibm.com<mailto:kdbutt@us.ibm.com> http://www-03.ibm.com/servers/storage/ From: Shawn Authement <Shawn.Authement@texmemsys.com><mailto:Shawn.Authement@texmemsys.com> To: t10@t10.org<mailto:t10@t10.org> Date: 09/24/2008 12:17 PM Subject: I_T nexus loss ________________________________ * From the T10 Reflector (t10@t10.org<mailto:t10@t10.org>), posted by: * Shawn Authement <Shawn.Authement@texmemsys.com><mailto:Shawn.Authement@texmemsys.com> * All, I am currently researching device behavior with respect to N_Port login and was wondering if anyone can provide clarification. Q: If an already-logged-in N_Port performs login again (via PLOGI), is this considered an I_T nexus loss as defined by SAM-3, 6.3.4? The ENDL Fibre Channel Bench Reference implies that re-Login causes an implicit Logout. However, I cannot find any supporting information in either the FCP-3 for FC-LS specifications. My goal is to ultimately determine whether a SCSI Target Port should set a Unit Attention if a SCSI Initiator Port re-logs in. Thank you for your your help! -- Shawn Authement Sr. Software Engineer Texas Memory Systems, Inc. Shawn.Authement@texmemsys.com<mailto:Shawn.Authement@texmemsys.com> ph: +1.713.266.3200 * * For T10 Reflector information, send a message with * 'info t10' (no quotes) in the message body to majordomo@t10.org<mailto:majordomo@t10.org>