Date: Wed, 11 Aug 1999 17:35:35 +0100 From: Josef Karthauser <joe@pavilion.net> To: Dag-Erling Smorgrav <des@flood.ping.uio.no> Cc: hackers@FreeBSD.ORG, fs@FreeBSD.ORG Subject: Re: Disk label recovery - request for suggestions. Message-ID: <19990811173535.Y88035@pavilion.net> In-Reply-To: <xzp672muw03.fsf@flood.ping.uio.no>; from Dag-Erling Smorgrav on Wed, Aug 11, 1999 at 06:23:24PM %2B0200 References: <19990808185112.A99557@pavilion.net> <xzpg11qv3nm.fsf@flood.ping.uio.no> <19990811171514.X88035@pavilion.net> <xzp672muw03.fsf@flood.ping.uio.no>
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On Wed, Aug 11, 1999 at 06:23:24PM +0200, Dag-Erling Smorgrav wrote: > Josef Karthauser <joe@pavilion.net> writes: > > Ahha - of course. Ok, let me re-phrase the question then. By looking > > at the contents of the superblocks on a UFS file system it's possible to > > reconstruct a disklabel for a slice. > > Well, it's possible to reconstruct the label information for *that > particular UFS file system*, since if you know the location of the > superblock (or one of its backup copies), you can determine the offset > and size of the FS. It won't tell you anything about *other* > partitions though. That's ok, because each slice has its _own_ label. If the bios partition table loses it's mind that's a little more work :). > > Is this trick possible with other kinds of file systems too? > > That's totally dependent on the particular file system. For instance, > a swap partition contains no metadata (that I know of), so all you can > do is deduce it's size and position from the sizes and positions of > surrounding partitions, and of the slice they're in. > What are the implications of adding a metadata structure to the swap structure. (It only needs a block :). [Although thinking out loud, it's complicated because there's no 'newfs' process that touches the partition, on the other hand the size of the partition is known at swap-mounting time, so the meta data could be written at that point.] Joe -- Josef Karthauser FreeBSD: How many times have you booted today? Technical Manager Viagra for your server (http://www.uk.freebsd.org) Pavilion Internet plc. [joe@pavilion.net, joe@uk.freebsd.org, joe@tao.org.uk] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message
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