Date: Sun, 26 May 2002 05:36:42 -0700 From: "Philip J. Koenig" <pjklist@ekahuna.com> To: Questions@FreeBSD.ORG Cc: Axel Scheepers <axel@axel.truedestiny.net> Subject: Re: Disk bad sector question Message-ID: <20020526123642862.AAA448@empty1.ekahuna.com@pc02.ekahuna.com> In-Reply-To: <20020526125120.B43810@mars.thuis> References: <20020519122229533.AAA405@empty1.ekahuna.com@pc02.ekahuna.com>; from pjklist@ekahuna.com on Sun, May 19, 2002 at 05:22:30AM -0700
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On 26 May 2002, at 12:51, Axel Scheepers boldly uttered: > On Sun, May 19, 2002 at 05:22:30AM -0700, Philip J. Koenig wrote: > > Yep, I already used camcontrol to view the original and grown defect > > lists after seeing these errors. > > > > And I know I can try copying data to the sectors in question and > > force them to be remapped, etc. But I want to take a look at the > > affected files first and recover as much as I can from them, before I > > do that. I didn't see how camcontrol would help in that respect. > > > > I guess I'd be rather surprised if there is no way to figure out > > which sectors are assigned to which inodes or files.. > > > > My bad, I read your post to quickly, sorry. > You might find the information in /usr/src/sys/ufs/ufs interesting, > mostly dinode.h I think. That contains the layout of an inode as it's > present on an ufs filesystem and contains an array of the disk > blocks it's using. Then you could try to read those sectors with dd, > I hear there's a modified version which handles i/o errors a bit better > but retrieving it will be a hard job. Not a problem. I found out one way to ascertain what files are affected -- do a dump/restore and see which files have errors either saving or restoring. :-) I found a few that way, but I'm sure there are others that wouldn't show up like that. Lucky for me, all the files were A) non-critical and B) part of the base system and thus rebuilt with make world. I've been using the new disk for a few days now. FWIW, I see Linux has some utilities which might come in handy on FreeBSD. One called "badblocks" that can find bad blocks and another called "dumpe2fs" (derived from Berkeley's "dumpfs") that with a -b option will also produce a list that can be used by "e2fsck" to mark the blocks bad. (looks like dumpfs might've told me what I wanted to know, if I had *any* idea how to decipher its output :-) Phil -- Philip J. Koenig pjklist@ekahuna.com Electric Kahuna Systems -- Computers & Communications for the New Millenium To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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