From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: Fwd: Re: [Scst-devel] linuxcon 2010... Date: Wed, 18 Aug 2010 15:43:08 -0500 Message-ID: <1282164188.10878.22.camel@mulgrave.site> References: <4C69653E.6050808@vlnb.net> <1282077040.16098.47.camel@mulgrave.site> <4C6C1DC1.8090208@vlnb.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4C6C1DC1.8090208@vlnb.net> Sender: linux-kernel-owner@vger.kernel.org To: Vladislav Bolkhovitin Cc: scst-devel , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On Wed, 2010-08-18 at 21:52 +0400, Vladislav Bolkhovitin wrote: > James Bottomley, on 08/18/2010 12:30 AM wrote: > >> 1. What don't you like in the transition path for users from STGT to > >> SCST, which I proposed: > >> > >> - The only people which would be affected by replacing of STGT by SCST > >> would be users of ibmvstgt. Other STGT users would not notice it at all. > >> Thus, we should update ibmvstgt for SCST. If ibmvstgt updated for SCST, > >> the update for its users would be just writing of a simple scstadmin's > >> config file. > >> > >> - STGT doesn't have backend drivers, which SCST doesn't have, so > >> there's nothing to worry here. At max, AIO support should be added to > >> fileio_tgt. > >> > >> - STGT user space targets can use SCST backend via scst_local module. > >> Scst_local module is ready and work very well. > >> > >> The result would be very clear without any obsolete mess. > > > > So does that get us up to being a drop in replacement? I think you're > > saying that even with all of this, at least the VSCSI part will need > > updating, so the answer seems to be "no". > > Sorry, I can't understand, "no" for which? For the whole transition > path, or just until there is a patch for ibmvstgt to become ibmvscst? No to the question "does that get us up to being a drop in replacement [for STGT]?" > >> 4. Have you changed your opinion that a driver level multipath is > >> forbidden in Linux and now you think that an iSCSI target with MC/S > >> support is acceptable? > > > > no; I still think MCS is a pointless duplication of multipath that only > > works for iSCSI. > > Then, does it mean that similarly as it was with open-iscsi, which had > to remove MC/S support to be able to be accepted into the mainline, an > iSCSI target can't go into mainline if it has MC/S? To be honest, I don't care about targets. I only care that the initiators do the right thing. James