From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Johannes Thumshirn To: Keith Busch Cc: Christoph Hellwig , Jens Axboe , linux-block@vger.kernel.org, Sagi Grimberg , linux-nvme@lists.infradead.org, Hannes Reinecke Subject: Re: [PATCH 8/9] nvme: implement multipath access to nvme subsystems References: <20170925134031.10548-1-hch@lst.de> <20170925134031.10548-9-hch@lst.de> <20170928155315.GK8463@localhost.localdomain> Date: Sat, 30 Sep 2017 21:37:38 +0200 In-Reply-To: <20170928155315.GK8463@localhost.localdomain> (Keith Busch's message of "Thu, 28 Sep 2017 09:53:16 -0600") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 List-ID: [+Cc Hannes ] Keith Busch writes: > On Mon, Sep 25, 2017 at 03:40:30PM +0200, Christoph Hellwig wrote: >> The new block devices nodes for multipath access will show up as >>=20 >> /dev/nvm-subXnZ > > Just thinking ahead ... Once this goes in, someone will want to boot their > OS from a multipath target. It was a pain getting installers to recognize > /dev/nvmeXnY as an install destination. I'm not sure if installers have > gotten any better in the last 5 years about recognizing new block names. We discussed (Hannes, Christoph and me) this as well offline this week and it should eithr be possible with some udev magic (fake a /dev/mapper/WWID symlink) or a shim device-mapper target that prevents dm-mpath from attaching to the underlying block devices and creates a real /dev/mapper/WWID device node (Christoph especially dislikes this). None of them are pretty, but probably all we can do so far. Byte, Johannes --=20 Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: Felix Imend=C3=B6rffer, Jane Smithard, Graham Norton HRB 21284 (AG N=C3=BCrnberg) Key fingerprint =3D EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850 From mboxrd@z Thu Jan 1 00:00:00 1970 From: jthumshirn@suse.de (Johannes Thumshirn) Date: Sat, 30 Sep 2017 21:37:38 +0200 Subject: [PATCH 8/9] nvme: implement multipath access to nvme subsystems In-Reply-To: <20170928155315.GK8463@localhost.localdomain> (Keith Busch's message of "Thu, 28 Sep 2017 09:53:16 -0600") References: <20170925134031.10548-1-hch@lst.de> <20170925134031.10548-9-hch@lst.de> <20170928155315.GK8463@localhost.localdomain> Message-ID: [+Cc Hannes ] Keith Busch writes: > On Mon, Sep 25, 2017@03:40:30PM +0200, Christoph Hellwig wrote: >> The new block devices nodes for multipath access will show up as >> >> /dev/nvm-subXnZ > > Just thinking ahead ... Once this goes in, someone will want to boot their > OS from a multipath target. It was a pain getting installers to recognize > /dev/nvmeXnY as an install destination. I'm not sure if installers have > gotten any better in the last 5 years about recognizing new block names. We discussed (Hannes, Christoph and me) this as well offline this week and it should eithr be possible with some udev magic (fake a /dev/mapper/WWID symlink) or a shim device-mapper target that prevents dm-mpath from attaching to the underlying block devices and creates a real /dev/mapper/WWID device node (Christoph especially dislikes this). None of them are pretty, but probably all we can do so far. Byte, Johannes -- Johannes Thumshirn Storage jthumshirn at suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg GF: Felix Imend?rffer, Jane Smithard, Graham Norton HRB 21284 (AG N?rnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850