SLUG Mailing List Archives
Re: [SLUG] Help I just destroyed my Root filesystem
- To: <andrew@xxxxxxxxxxx>
- Subject: Re: [SLUG] Help I just destroyed my Root filesystem
- From: "Richard Heycock" <rgh@xxxxxxxxxxxxxxx>
- Date: Fri, 13 Jun 2003 16:14:13 +1000 (EST)
- Cc: slug@xxxxxxxxxxx
> On Fri, 13 Jun 2003, Richard Heycock wrote:
>> I'm new to this list and I need some help! I just ran grub-install on
>> my root partition instead of my boot partition and it appears to have
>> wreaked it.
>> If I run file -s /dev/hda5 I now get 'x86 boot sector' instead of
>> 'ReiserFS V3.6 block...' and I can no longer mount it.
>> When the machine tries to boot it loads the kernel (from /dev/hda6)
>> but when it comes to mount the root partition it kernel panics as it
>> cannot mountthe filesystem.
>> I know at least some of the data is on the partition (`less
>> /dev/hda5`). I'm guessing that grub-install has overwritten N number
>> of bytes at the beginning of the partition but beyond that I'm at a
>> complete loss at what to do.
> Your probably not in too bad shape. The boot sector is just a single
Arr nice to hear some positive thoughts :-) I've only been met with stoney
silence on other lists (debian-users and reiserfs), though I'm told there
are these things called time zones...
> sector, and the rest of the drive should be untouched. The trick is
> recovering that first sector.
When you say sector do you mean the sector as in the disc drive or something
> Your basic tool for moving stuff around is dd which you can use to copy
> just the first sector from one file (ie probably a device file) to
> I don't know the details of ReiserFS. There's a good chance though
> that the first sector contains only really generic stuff, and/or there
> are backups stored elsewhere on the device. You might even find it's
> as easy as copying the first sector (only) from a healthy ReiserFS file
> system to your damaged one. There's nothing on that sector you're
> trying to save, so just give it a whirl, but DONT MOUNT THE FILE SYSTEM
> IN OTHER THAN READ ONLY MODE until you're pretty sure its OK, and then
> consider copying the most important files out of the file system when
> it becomes accessible.
The first thing I did was to dd the entire partition on to another partition
so I've got some scope for experiment.
I've dd'ed the first 512 bytes from a healthy reiserfs partition but without
success. I also tried to 'strace grub-install' to see how much data was
being copied to the disc but I got an error message (something about the
bios) but I am trying to do this from within Knoppix so things are unlikely
to be the same.
> If it's not so happily simple and the first sector contains the root of
> your file system, device parameters or something similar, then the
> place to get help is probably a developers list for the ReiserFS file
I posted a message to this list but I haven't heard anything back yet, I'll
wait and see what happens this evening. I'm in a bit of a panic at the
moment so I'm trying everything I can think of!
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