From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 7 Jun 2000 19:43:35 +0200 From: "Heinz J. Mauelshagen" Subject: Re: [linux-lvm] Reliability Message-ID: <20000607194335.B17473@hmsysv.t-online.de> Reply-To: Mauelshagen@Sistina.com References: <20000607190757.A18846@gondor.com> Mime-Version: 1.0 In-Reply-To: <20000607190757.A18846@gondor.com>; from jan@gondor.com on Wed, Jun 07, 2000 at 07:07:57PM +0200 Sender: owner-linux-lvm Errors-To: owner-linux-lvm List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jan Niehusmann Cc: 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. Heinz On Wed, Jun 07, 2000 at 07:07:57PM +0200, Jan Niehusmann wrote: > What happens when one of several drives in a vg fails? Is the whole vg > lost or only lv's that are on that pv? In the latter case, what about > lv's that are only partly located on that pv? > > I once observed that with a corrupted partition table, causing one pv > to be lost, the whole vg didn't get detected. As I was able to reconstruct > the partition table, I didn't try very hard to get the vg running > without that drive. > > Jan -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Heinz Mauelshagen Sistina Software Inc. Senior Consultant/Developer Bartningstr. 12 64289 Darmstadt Germany Mauelshgen@Sistina.com +49 6151 710386 FAX 710396 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-