Re: "Cannot find file system superblock" error - how to recover?

From: Sergey 'DoubleF' Zaharchenko (doublef_at_tele-kom.ru)
Date: 01/07/04

  • Next message: Sergey 'DoubleF' Zaharchenko: "Re: How to create .iso file image of cdrom (atapi)?"
    Date: Wed, 7 Jan 2004 08:10:31 +0300
    To: scott@sremick.net
    
    
    

    On Tue, 6 Jan 2004 11:39:57 -0800 (PST)
    "Scott I. Remick" <scott@sremick.net> probably wrote:

    >
    > --- Sergey 'DoubleF' Zaharchenko <doublef@tele-kom.ru> wrote:
    > > I think you already have a copy (the data at offset 32 seems to be it).
    > > If you want, do a
    > >
    > > # dd if=/dev/ad6s1 skip=16 count=16 of=/some/file
    >
    > ok, done. Is there a way to use fsck_ufs -b now to fix this? Or is that
    > premature? And if I remember correctly, that doesn't actually APPLY the
    > alternate superblock... it just allows fsck to run while utilizing an
    > alternate one. So we need to use some sort of dd command to copy it to the
    > proper location, correct?
    >
    > > Please tell me everything what you tried to use to mount/fsck the drive
    > > (and the results, of course).
    >
    > Well, my memory is sketchy so I don't know how much use it'd be. But I was
    > saving a file to /data (ad6) when the system hung. Then it rebooted on its
    > own. Of course fsck ran on bootup but it gave up and told me I had to run it
    > manually. When I did (I don't remember any parameters I specifically used,
    > if any) I got:
    >
    > /dev/ad6s1c
    > Cannot find file system superblock
    > /dev/ad6s1c: NOT LABELED AS A BSD FILE SYSTEM
    >
    > I remember there being some of the other common message for little things
    > that you just tell it to go ahead and fix. But the above error was a brick
    > wall and would keep me from going multi-user. Ultimately I had to
    > comment-out the line in fstab:
    >
    > #/dev/ad6s1c /data ufs rw 2 2
    >
    > So I could at least boot. And that's the way I've been ever since.
    >
    > Trying to mount it now gives:
    >
    > su-2.05b# mount -r /dev/ad6s1c /data
    > mount: /dev/ad6s1c on /data: incorrect super block
    >
    > And so we stand.
    >
    > > Try booting from a 4.x floppy and doing it all over again... The FS is
    > > UFS1, isn't it?
    >
    > Ummm... doing what all over again?

    I mean trying to mount it, to fsck it, using dd|hd to find the
    superblock, etc. I just want to be *really* sure we know what
    we are doing.

    While we are on that, do you have an empty disk to copy this disk's
    contents to? I'm not sure, but maybe I have an idea...

    > Wipe the disk and redo the partitions? I
    > hope we're not quite there yet. How does using 4.x give me an advantage over
    > 5.1? I'm not clear on that part.

    Simplicity.

    >
    >
    > _______________________________________________
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    >

    -- 
    DoubleF
    Lackland's Laws:
    	(1) Never be first.
    	(2) Never be last.
    	(3) Never volunteer for anything
    
    



  • Next message: Sergey 'DoubleF' Zaharchenko: "Re: How to create .iso file image of cdrom (atapi)?"

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