From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe Varoqui Subject: RE: [PATCH] [RFC] switch DM tables to readonly automatically Date: Wed, 30 Apr 2008 10:19:51 +0200 Message-ID: <1209543591.26745.9.camel@plop> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Hannes Reinecke Cc: device-mapper development List-Id: dm-devel.ids > Hi all, >=20 > this patch switches the device-mapper table to read-only status automat= ically if one underlying device returns -EROFS. >=20 > Rationale: > Whenever a SCSI device is switched to read-only a table reload from mul= tipath-tools fails, without any indication about the reason. And it's act= ually quite tricky to detect the read-only status from userland. And quit= e pointless, too, as the kernel already knows about it. >=20 > And we now can create tables for CD-ROMs, too, without having to use th= e '-r' flag to dmsetup ... >=20 > Christophe, this might also fix your problem. >=20 It seems it will solve the map creation error on read-only LU, but what a= bout these LU becoming writable ? ... as is the case with the Symmetrix R2 upon spliting the synchronisation li= nk. Will the devmap become writable too automagically or is the multipathd da= emon expected to take action the promote the map RW ? Thanks for caring anyway. > As usual, comments etc are welcome. >=20 > Cheers, >=20 > Hannes > -- > Dr. Hannes Reinecke zSeries & Storage > hare suse de +49 911 74053 688 > SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg > GF: Markus Rex, HRB 16746 (AG N=C3=BCrnberg) >=20