topic Re: Bad superblock in Operating System - HP-UX

Bad superblock

Jeremy Loukinas_1 — Fri, 03 Jan 2003 16:01:07 GMT

hpserv220:/ # fsck /dev/vg06/rlvol4
** /dev/vg06/rlvol4
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(1M).
hpserv220:/ #

any suggestions how to resovle this? Running a standard fsck results in the above error. Where does HPUX store its alternate super block?

Jeremy
Sunadmin@jslracing.com

Re: Bad superblock

Sridhar Bhaskarla — Fri, 03 Jan 2003 16:06:42 GMT

Hi,

What filesystem is this?. If it is vxfs, then try

fsck -F vxfs /dev/vg06/rlvol4.

-Sri

Re: Bad superblock

Patrick Wallek — Fri, 03 Jan 2003 16:07:09 GMT

First off, I am assuming that this is an HFS filesystem since you got the above error.

From the 'man fsck_hfs' man page:

-b blocknum
Use the specified blocknum as the superblock for the file system. An alternate superblock can usually be found at block ((SBSIZE+BBSIZE)/DEV_BSIZE), typically block 16. DEV_BSIZE is defined in . You can also find a list of alternate superblocks in /var/adm/sbtab (see mkfs(1M)).

So try:

# fsck -b 16 /dev/vg06/rlvol4

If that doesn't work, have a look in /var/adm/sbtab for other alternate superblock locations to use with the '-b' option.

Re: Bad superblock

Dietmar Konermann — Fri, 03 Jan 2003 16:08:18 GMT

Are you sure that this isn't a VxFS? Maybe the fsck wrapper failed to recognize the fs type and accidently used the hfs fsck.

Check /etc/fstab for your fs type. If it's vxfs try:

fsck -F vxfs /dev/vg06/rlvol4

Otherwise (for hfs!) check /etc/sbtab for alternate hfs superblocks.

Best regards...
Dietmar.

Re: Bad superblock

Paul Sperry — Fri, 03 Jan 2003 16:10:29 GMT

there is allways a spare superblock at 16
HFS?
try:

fsck -F hfs -b 16 dev/vg06/rlvol4

Re: Bad superblock

Martin Johnson — Fri, 03 Jan 2003 16:13:20 GMT

The list of alternate superblocks is in /var/adm/sbtab. Use "fsck_hfs -b" to specify the alternate superblock.

HTH
Marty

Re: Bad superblock

Jose Mosquera — Fri, 03 Jan 2003 16:19:09 GMT

Hi,

FYI..

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90681/B2355-90681_top.html&con=/hpux/onlinedocs/B2355-90681/00/01/102-con.html&toc=/hpux/onlinedocs/B2355-90681/00/01/102-toc.html&searchterms=superblock%7cbad&queryid=20030103-090539

Bye