Return-Path: X-Sieve: cmu-sieve 2.0 Return-Path: Received: from bache.ece.cmu.edu (BACHE.ECE.CMU.EDU [128.2.129.23]) by ece.cmu.edu (8.11.0/8.10.2) with ESMTP id h442d6S21194 for ; Sat, 3 May 2003 22:39:06 -0400 (EDT) Received: by bache.ece.cmu.edu (Postfix, from userid 953) id B6F2283; Sat, 3 May 2003 22:39:05 -0400 (EDT) Received: from sos.ece.cmu.edu (SOS.ECE.CMU.EDU [128.2.129.27]) by bache.ece.cmu.edu (Postfix) with ESMTP id D7E6074; Sat, 3 May 2003 22:39:01 -0400 (EDT) Received: by sos.ece.cmu.edu (Postfix) id D80418952; Sat, 3 May 2003 22:38:46 -0400 (EDT) Received: from hazard.ece.cmu.edu (HAZARD.ECE.CMU.EDU [128.2.129.24]) by sos.ece.cmu.edu (Postfix) with ESMTP id BDB198950 for ; Sat, 3 May 2003 22:38:46 -0400 (EDT) Received: by hazard.ece.cmu.edu (Postfix) id 8F55370; Sat, 3 May 2003 22:38:46 -0400 (EDT) Received: by hazard.ece.cmu.edu (Postfix, from userid 953) id 6FF1279; Sat, 3 May 2003 22:38:46 -0400 (EDT) Received: from sos.ece.cmu.edu (SOS.ECE.CMU.EDU [128.2.129.27]) by hazard.ece.cmu.edu (Postfix) with ESMTP id 1ED6F70 for ; Sat, 3 May 2003 22:38:44 -0400 (EDT) Received: by sos.ece.cmu.edu (Postfix, from userid 363) id E4E4E8953; Sat, 3 May 2003 22:38:43 -0400 (EDT) X-Original-To: ips@sos.ece.cmu.edu Received: from bache.ece.cmu.edu (BACHE.ECE.CMU.EDU [128.2.129.23]) by sos.ece.cmu.edu (Postfix) with ESMTP id 3200D8950 for ; Sat, 3 May 2003 22:38:42 -0400 (EDT) Received: by bache.ece.cmu.edu (Postfix) id BC99D74; Sat, 3 May 2003 22:38:41 -0400 (EDT) Delivered-To: ips@ece.cmu.edu Received: by bache.ece.cmu.edu (Postfix, from userid 953) id A3E887B; Sat, 3 May 2003 22:38:41 -0400 (EDT) Received: from lion.ninthwonder.com (lion.ninthwonder.com [151.199.66.147]) by bache.ece.cmu.edu (Postfix) with ESMTP id C72F076 for ; Sat, 3 May 2003 22:38:38 -0400 (EDT) Received: by lion.ninthwonder.com (Postfix, from userid 1021) id 91BFA30706; Sat, 3 May 2003 22:38:24 -0400 (EDT) Date: Sun, 4 May 2003 02:38:10 +0000 (UTC) From: wrstuden@wasabisystems.com X-X-Sender: wrstuden@neverwinter.home-net.icnt.net To: Eddy Quicksall Cc: "Mallikarjun C." , ips@ece.cmu.edu Subject: RE: iSCSI: clearing SCSI objects In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-ips@ece.cmu.edu Precedence: bulk X-Spam-Status: No, hits=-37.2 required=5.0 tests=BAYES_01,EMAIL_ATTRIBUTION,IN_REP_TO,NO_REAL_NAME, QUOTED_EMAIL_TEXT,REFERENCES,REPLY_WITH_QUOTES, USER_AGENT_PINE version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) On Fri, 2 May 2003, Eddy Quicksall wrote: > Thanks for making me more aware. > > Actually what I'm looking for is a sure fire way I can release resources for > a SCSI Initiator Port (InitiatorName+ISID) after session closure (assuming > there are no outstanding persistent reservations). > > Understanding "I_T Nexus Loss" better brings up another point regarding > this: > > Section 6.3.4 of SAM-3R6 says that the target shall establish a unit > attention for the SCSI initiator port. But the SCSI initiator port is > identified via the ISID. That means after a session closure (in my case via > a session logout), the target needs to still keep state information for each > ISID that was ever used. > > That can be a burden on the target's resources. Especially if the initiator > device uses a different ISID for each login. I don't think we need to worry about that. One of the things iSCSI has that parallel SCSI didn't have is that you can notice when you lost the connection. I_T nexus loss UA was needed before, since you wouldn't necessarily notice it. Since you will notice it with iSCSI, I think we're fine. After all, the initiator will know, and can pass such a UA up its stack. Note I'm assuming we're talking about cases where the initiator is just as likely to notice the nexus loss as the target. If for some reason we could have an I_T nexus loss w/o the initiator noticing (a nexus loss that isn't a session loss, not sure what that'd really be), then yes, we should assert a UA. Take care, Bill