bad superblock

 
Gonzalo Tipola
Occasional Contributor

bad superblock

Dear Admins,
I have a box with HP-UX 10.00, that gives the following error at boot time:

/dev/vg00/lvol1: BAD SUPER BLOCK: MAGIC NUMBER WRONG

USE -b OPTION TO FSCK TO SPECIFY LOCATION OF AN ALTERNATE

SUPER-BLOCK TO SUPPLY NEEDED INFORMATION; SEE fsck

Then, I tried to run the following command:

bcheckrc# fsck â F hfs â b 16 /dev/vg00/rlvol1

but this it was not successful.

In the file /var/adm/sbtab there is not entry for /dev/adm/rlvol1.

Some suggestion to recover this system.


TIA

Gonza
7 REPLIES 7
Steven E. Protter
Exalted Contributor

Re: bad superblock

Script:

#!/usr/bin/sh
# /dev/vg01/rlvol2 example
echo "A files system check on parameter 1 is commencing\n"
fsck -F vxfs -o full -y $1

If that doesn't work, you're looking at Ignite recovery(make_tape_recovery).

SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
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Founder http://newdatacloud.com
Michael Steele_2
Honored Contributor

Re: bad superblock

For HFS file systems CAT out /etc/sbtab and select one of the 100 or so numbers under /stand. They should all be a power a 2. Then use this version of 'fsck':

# fsck -F hfs -b #### /stand
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Suresh Patoria
Super Advisor

Re: bad superblock

Hi,

First start the system in single user mode

then open the /var/adm/sbtab

use anyone of those number

with fsck command

#fsck -F hfs -b <> -o full /dev/vg00/rlvol1

Thanx
T G Manikandan
Honored Contributor

Re: bad superblock

you can check /etc/sbtab for the alternate super block

#fsck -F hfs -b 16 /dev/vg00/lvol1

Just try using lvol1 instead of rlvol1
Bill Hassell
Honored Contributor

Re: bad superblock

Generally, when the alternate superblock 16 does not work, the filesystem has been trashed beyond repair. Time to get the backup tapes.


Bill Hassell, sysadmin
Bruno Ganino
Honored Contributor

Re: bad superblock

#fsck -g
It fix problems without risk of data loss (bad free list, dirty superblock,etc.).
If any serious damage is encountered that cannot be repaired without risk of data loss, it terminates with a warning message.

Bruno
Torino (Turin) +2H
George Petrides_1
Honored Contributor

Re: bad superblock

I agree with Bill, who's comment is great for all the newbies who claim "Who does tape backups anymore? Just disk backups are fine!"
George