From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [127.0.0.1] (sebastian-int.corp.redhat.com [172.16.52.221]) by pobox.fab.redhat.com (8.13.1/8.13.1) with ESMTP id l4E8iGr1001085 for ; Mon, 14 May 2007 04:44:17 -0400 Message-ID: <46481FEF.802@redhat.com> Date: Mon, 14 May 2007 09:38:07 +0100 From: "Bryn M. Reeves" MIME-Version: 1.0 Subject: Re: [linux-lvm] LVM on SATA/PATA disks References: In-Reply-To: Content-Transfer-Encoding: 7bit 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: LVM general discussion and development -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Stuart D. Gathman wrote: > If out of order writes are enabled, then your server should hold power > to the disk drives for part of a second after disabling further writes > in software. LVM is a low risk because LVM changes are comparatively > rare, and the modification window is small. But, theoretically, if > you lost power right at the instant you pressed return on lvcreate, > lvextend, or lvremove, on a system with busy disk io, you could corrupt > the LVM metadata. LVM metadata I/O does not pass through device-mapper unless you are stacking volume groups so I'm not sure how your comment regarding barriers is relevant here. It's also only going to affect devices under snapshot and multipath mappings. How does this differ from updating an MSDOS or GPT partition table, for example? Kind regards, Bryn. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFGSB/v6YSQoMYUY94RAubIAJ4vcB/tqherGhmW/M6n1wcO5KGungCffw1w ISfLoRVk6CP3EryIzHTolXA= =g18w -----END PGP SIGNATURE-----