From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx02.extmail.prod.ext.phx2.redhat.com [10.5.110.6]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id n8I1MxjV025442 for ; Thu, 17 Sep 2009 21:22:59 -0400 Received: from mail-yw0-f174.google.com (mail-yw0-f174.google.com [209.85.211.174]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n8I1Mmpx000446 for ; Thu, 17 Sep 2009 21:22:48 -0400 Received: by ywh4 with SMTP id 4so787033ywh.6 for ; Thu, 17 Sep 2009 18:22:48 -0700 (PDT) Sender: Benjamin Kingston Message-ID: <4AB2E0E4.70205@gmail.com> Date: Thu, 17 Sep 2009 18:22:44 -0700 From: Ben Kingston MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [linux-lvm] Curious about LVM PV failure and mitigation Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-lvm@redhat.com I've been wondering for a while what happens if a drive fails that is part of a VGroup (spanned across PV's, not Raid0), specifically in a active VG. Does LVM continue working as though there was a large sector failure? What happens if the first physical drive that the VG was created on fails? Is the entire Volume lost? I've hypothosized a mitigation method for the first physical drive failing. I would create the VG on an SD card so that all of the metadata would be stored there, and if a moving drive fails, it wouldn't take the LVM with it. This would also an easy way to have a remote dd image of any other important volume metadata (e.g. Luks). But before I do this, I'd like some ideas on paramaters. Would turning on the write protect lock cause any issues, after all PV's are added, to writing to the HDD with EXT4? What would be an optimal SD size? I'm guessing 256MB would be sufficient, but I don't want to worry about messing up EXT4's superblocks. Thanks for the help.