From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200006080031.CAA16192@e35.marxmeier.com> Subject: Re: [linux-lvm] Reliability Date: Thu, 08 Jun 2000 2:31:19 MESZ In-Reply-To: <20000607194335.B17473@hmsysv.t-online.de>; from "Heinz J. Mauelshagen" at Jun 7, 100 7:43 pm From: Michael Marxmeier Sender: owner-linux-lvm Errors-To: owner-linux-lvm List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mauelshagen@Sistina.com Cc: jan@gondor.com, linux-lvm@msede.com > Quorum support is a solution to deal with the activation of a VG without having > all PVs available which belong to it. > > This actually is usefull in case you have associated all LEs of specific LVs > to available PVs and want to access those. > In real life scenarios this can't be garanteed though which leads to partitally > destroyed (unusable) LV contents and in consequence to filesystem errors. > > Therefore qourum is IMO not really usefull. > > The tradeoff of the existing solution nevertheless is that reconstruction of > the partition table and the VGDA is necessary on a replacement disk (subsystem) > which takes some time :-{( > After this we almost have the same scenario as with quorum. > The difference is that no I/O errors are returned in case of accessing > bad LEs. As far as i can see Quorum support looks like the saner option: If you loose a disk and only restore the partition table and VGDA the replacement disk still mostly contains garbage (eg. not a fs). So we could as well activate the VG and leave LVs with extents on offline PVs disabled? Any reason why this might not work? Michael -- Michael Marxmeier Marxmeier Software AG E-Mail: mike@msede.com Besenbruchstrasse 9 Phone : +49 202 2431440 42285 Wuppertal, Germany Fax : +49 202 2431420 http://www.msede.com/