how to fix bad superblock
d.forsyth at ru.ac.za
Mon Jul 18 14:49:30 UTC 2011
After a hardrive let the smoke out last week, part of a 4 drive RAID
array, I am now battling to get back into the array.
I have replaced the bad drive and it has been rebuilt (Intel Matrix
Raid on the motherboard).
some partitions are ok but had lots of errors fsck fixed, others
BAD SUPER BLOCK: VALUES IN SUPER BLOCK DISAGREE WITH THOSE IN FIRST
it then asks if it must look for alternates but claims 32 is not one
and stops. All my partitions are UFS so why doesn't it look at block
'newfs -N ar0s1f' displays a lot of copies of the superblock.
Google show that this error happens to a lot of folks,a nd there is
no tool for fixing it. fsck_ufs will use an alternate superblock,
prompt you to update the master block, and then NOT do it, the error
I used a dd command I found on the web to copy an alternate SB to the
master superblock, and fsck still shows the message as above.
I then copied the 2nd alternate to both the master and the 1nd
alternate superblock positions, and it STILL reports a mismatch.
Please tell me, how do I fix this. ar0s1f is discardable which is
why I am trying to fix it first. /home has stuff I want to recover
and it also has a bad superblock.
The stuff I googled shows that there is confusion about block sizes.
When 'newfs -N' shows a copy at block 160, what block size does it
mean? the 16384 it shows in its display for this partition, or the
default of 512?
DA Fo rsyth Network Supervisor
Principal Technical Officer -- Institute for Water Research
More information about the freebsd-questions