From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: Fwd: Re: [Scst-devel] linuxcon 2010... Date: Sat, 21 Aug 2010 15:38:48 -0500 Message-ID: <1282423128.3015.35.camel@mulgrave.site> References: <4C69653E.6050808@vlnb.net> <1282077040.16098.47.camel@mulgrave.site> <4C6C1DC1.8090208@vlnb.net> <1282164188.10878.22.camel@mulgrave.site> <4C702030.2070306@vlnb.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cantor.suse.de ([195.135.220.2]:43331 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121Ab0HUUix (ORCPT ); Sat, 21 Aug 2010 16:38:53 -0400 In-Reply-To: <4C702030.2070306@vlnb.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Vladislav Bolkhovitin Cc: scst-devel , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org On Sat, 2010-08-21 at 22:51 +0400, Vladislav Bolkhovitin wrote: > James Bottomley, on 08/19/2010 12:43 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]?" > > I'm sorry again, I did my best, but still can't understand. What you > wrote looks for me too ambiguous. My English must be too bad.. > > Could elaborate more for what the "no" is, please? What don't you like > in the plan I suggested? No it isn't a plan that gives us a drop in replacement for STGT. I didn't say migration path to random userspace target, I said reuse of existing code. James