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: Gautam Gopalakrishnan: "Re: changing configure options when using a port" 
    Date: Tue, 6 Jan 2004 14:39:28 +0300
To: Malcolm Kay <malcolm.kay@internode.on.net>

    On Tue, 6 Jan 2004 19:57:09 +1030
    Malcolm Kay <malcolm.kay@internode.on.net> probably wrote:

    > On Tue, 6 Jan 2004 15:38, Scott I. Remick wrote:
    > > --- Sergey 'DoubleF' Zaharchenko <doublef@tele-kom.ru> wrote:
    > > > > 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.
    > >
    > > Ok, sounds like a plan. Not that I know what I'm doing. Should I use
    > > something like the following command to save my current disklabel?
    > >
    > > bsdlabel /dev/ad6s1c > disklabel.ad6s1c.backup
    > >
    > > Then do I just edit a copy of that textfile, change the offsets to 0, then
    > > write it back like this?
    > >
    > > bsdlabel -R /dev/ad6s1c dislabel.ad6s1c.new
    > >

    And maybe prefix that by a

    $ bsdlabel -R /dev/ad6s1c dislabel.ad6s1c.new

    which would just check your new layout for errors, without writing
    anything, and print your file out as disklabel understands it.

    > > And lastly... your talk about offsets. The man page for bsdlabel describes
    > > using it on the whole disk (ad6) and not a slice or partition. If I run it

    It can't be fdisk that you are reading about?

    > > on ad6, I get:
    > >
    > > bsdlabel: /dev/ad6: no valid label found
    > >
    >
    > Beware; if you write a disklabel (or presumably bsdlabel; I have no experience
    > with 5.x) to ad6 you create a "dangerously dedicated"
    > disk, i.e. a disk without slices.

    And of course the label isn't there, just because nobody wanted a `DD' disk.

    > > If I run it on the slice ad6s1 I get:
    > >
    > > # /dev/ad6s1:
    > > 8 partitions:
    > > # size offset fstype [fsize bsize bps/cpg]
    > > c: 156344517 0 unused 0 0 # "raw" part,
    > > don't edit
    > > e: 156344517 0 4.2BSD 2048 16384 89
    > >
    > > And there I see the offset of 0 you might be talking about...? Are we
    > > looking at the proper label? Just want to make sure before I mess things
    > > up.
    > >
    >
    > Are you saying that the disklabels reported for ad6s1 and ad6s1c are different?

    And the `new' one seems to be correct for a 80G drive (+- a couple of
    megabytes)? Have you touched anything?

    Now, mount might work.

    > Under FreeBSD 4.x ad6s1 and ad6s1c would normally be aliases referencing the
    > entire slice. Maybe 5.x is different! I'm now very confused.

    Uhum. disklabel said that the offset was 63 in your previous posting, didn't it?
    What does

    # ls -l /dev/ad6s1 /dev/ad6s1c

    say? Any differences? I have none.

    > What is reported by fdisk?

    Let me guess: a single large slice.

    > Malcolm Kay
    >
    > > Thanks!
    >
    > _______________________________________________
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    > 

    -- 
DoubleF
[Sir Stafford Cripps] has all the virtues I dislike and none of the
vices I admire.
		-- Winston Churchill

  • Next message: Gautam Gopalakrishnan: "Re: changing configure options when using a port"

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