From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH RFC 2/2] implement transport scan callout for iscsi Date: Tue, 24 May 2005 18:17:58 -0500 Message-ID: <1116976678.7710.34.camel@mulgrave> References: <42936441.0b798bab.39a4.ffff9774SMTPIN_ADDED@mx.googlegroups.com> <42939610.3070104@cs.wisc.edu> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from stat16.steeleye.com ([209.192.50.48]:42717 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S262157AbVEXXSH (ORCPT ); Tue, 24 May 2005 19:18:07 -0400 In-Reply-To: <42939610.3070104@cs.wisc.edu> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Mike Christie Cc: open-iscsi@googlegroups.com, 'SCSI Mailing List' On Tue, 2005-05-24 at 14:01 -0700, Mike Christie wrote: > > It's a leading transport connection of the session1 (above). Quoting the > > spec (http://www.faqs.org/rfcs/rfc3720.html): > > > > - According to [SAM2], the I_T nexus is a relationship > > between a SCSI Initiator Port and a SCSI Target Port. For iSCSI, > > this relationship is a session, defined as a relationship between > > an iSCSI Initiator's end of the session (SCSI Initiator Port) and > > the iSCSI Target's Portal Group. > > > > The session itself is not a "physical connection"; it aggregates one or more > > transport connections between a given SCSI Initiator Port and a SCSI Target > > Port. There is always at least one (leading) connection. > > > > So just to be clear, open-iscsi can support multiple connections per > session. Do you want us to completely remove this feature for mainline? > I know you and christoph have given me this answer many times before, > but not seeing a reply to Nicholas's question about just disabling may > have created some doubt as to the extent people have to go? Since > open-iscsi pushed the connection management code to userspace, removing > MCS from the driver will not be too terrible a job for us though. > > The connection dir for single connection sessions though is just a nice > way to export the kernel structure's info and have it also reflect the > iSCSI RFC's definitions at the same time. For sfnet we used to throw > everything in one dir becuase it did not have a connection structure so > it simplified refcounting. My current position on MC/S is that it runs counter to the no multi- pathing in the drivers policy, so should not be done. As far as I can see it's an optional add on to the iSCSI standard which doesn't improve the feature set or provide any value add over the mandatory explicit multi-path support in rfc3720, which is easy to do via dm-multipath. James