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

From: Sergey 'DoubleF' Zaharchenko (doublef_at_tele-kom.ru)
Date: 01/06/04

  • Next message: Wes Peters: "(no subject)" 
    Date: Tue, 6 Jan 2004 07:35:19 +0300
To: Malcolm Kay <malcolm.kay@internode.on.net>

    On Tue, 6 Jan 2004 13:29:26 +1030
    Malcolm Kay <malcolm.kay@internode.on.net> probably wrote:

    > On Tue, 6 Jan 2004 10:59, Scott I. Remick wrote:
    > > Sorry for the delay... holidays had me busy.

    Me too:)

    > > Hopefully you're still around
    > > and interested in picking up where we left off. I think we're definitely
    > > onto something...
    > >
    >
    > Looking back over some of your e-mails I find:
    > QUOTE
    > su-2.05b# disklabel -r /dev/ad6s1c
    > # /dev/ad6s1c:
    > 8 partitions:
    > # size offset fstype [fsize bsize bps/cpg]
    > c: 156344517 63 unused 0 0 # "raw" part, don't
    > edit
    > e: 156344517 63 4.2BSD 2048 16384 89
    > partition c: partition extends past end of unit
    > disklabel: partition c doesn't start at 0!
    > disklabel: An incorrect partition c may cause problems for standard system
    > utilities
    > partition e: partition extends past end of unit
    >
    > That doesn't look good.
    > ENDQUOTE
    >
    > The 63 offset is spurious. I've seen this before somewhere but can't
    > remember the details -- i.e the value 63.

    I know where you've seen this. The normal offset for the first *slice*
    is 63 sectors, for some historical reasons (those extra sectors were to
    be used for bad block replacement or something like that).

    Not sure how the 63 made it into the disklabel, though.

    > I wonder whether editing the label and setting both offsets to 0
    > might solve the problem.

    It definitely seems like that, as the actual offset of the partition is
    0, as dd shows.

    > You could always make a copy of the existing label
    > and put it back if the changes don't help.
    >
    > You could in addition check the size for the partitions against the size given by
    > fdisk for the slice.
    >
    > Malcolm Kay
    > _______________________________________________
    > freebsd-questions@freebsd.org mailing list
    > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
    > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
    > 

    -- 
DoubleF
Never settle with words what you can accomplish with a flame thrower.

  • Next message: Wes Peters: "(no subject)"

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