Re: Kernel panic, SB validate failed

[Steve Lord <lord@xxxxxxxx>]

Gaspar Bakos wrote:

> Hi,
>
> Just a couple of debug notes in reference to my previous email. These are
> the typical messages I get when xfs_checking the partitions on the disk
> (booted in a previous xfs linux from another disk):
>  

Something very wierd has happened to your device, all the magic numbers it
is complaining about are almost correct:

0x58665362 is bSfX it is supposed to be BSFX

0x496e is nI, it is supposed to be NI

So it almost looks like your device got case flipped on every other 
byte. However
if you look at the correct values vs the wrong ones, what is actually 
happening is
that a bit is getting pulled high in every 16 bit quantity. This caused 
B to become
b, F to become f and N to turn into n.

I would blame hardware here - possibly a cable is out of spec, or has come
loose, I cannot see software ever causing this type of corruption.

Having said that, your disk may still be bad, because you may have had
bad data written onto it.

Steve


> --------------------------------------
> [root@cfhat root]# xfs_check /dev/hdd5
> xfs_check: unexpected XFS SB magic number 0x58665362
> bad superblock magic number 58665362, giving up
>
> -----------------------------------
> [root@cfhat /]# xfs_check /dev/hdd7
> bad magic number 0x496e for inode 128
> bad magic number 0x496e for inode 129
> bad magic number 0x496e for inode 130
> bad magic number 0x496e for inode 131
> bad magic number 0x496e for inode 132
> bad magic number 0x496e for inode 133
> bad magic number 0x496e for inode 134
> ...
>
> bad magic number 0x496e for inode 769216
> bad magic number 0x496e for inode 769217
> bad magic number 0x496e for inode 769218
> ...
> bad magic number 0x496e for inode 769247
>
> bad magic number 0x496e for inode 1684000
> ...
> bad magic number 0x496e for inode 1684031
> root inode 128 is not a directory
> block 0/12 type unknown not expected
> block 0/13 type unknown not expected
> block 0/46 type unknown not expected
> ...
> disconnected inode 72210, nlink 1
> disconnected inode 72211, nlink 1
> disconnected inode 72212, nlink 1
> disconnected inode 72213, nlink 1
> ...
> link count mismatch for inode 128 (name ?), nlink 0, counted 17
> allocated inode 129 has 0 link count
> allocated inode 130 has 0 link count
> link count mismatch for inode 131 (name ?), nlink 0, counted 22
> ...
> link count mismatch for inode 524443 (name ?), nlink 2, counted 1
> link count mismatch for inode 633260 (name ?), nlink 4, counted 3
> block 2/6028 type unknown not expected
> block 2/6093 type unknown not expected
> ...
>
> -----------------
> [root@cfhat /]# xfs_check /dev/hdd8
> xfs_check: unexpected XFS SB magic number 0x58665362
> bad superblock magic number 58665362, giving up
>
> -------------------
> [root@cfhat /]# xfs_check /dev/hdd10
> bad magic number 0x496e for inode 25166464
> bad magic number 0x496e for inode 25166465
> bad magic number 0x496e for inode 25166466
> ...
> agi unlinked bucket 15 is 61967 in ag 6 (inode=25227791)
> agi unlinked bucket 35 is 209955 in ag 6 (inode=25375779)
> agi unlinked bucket 50 is 690 in ag 6 (inode=25166514)
> block 0/238 type unknown not expected
> link count mismatch for inode 175 (name ?), nlink 2, counted 1
> link count mismatch for inode 2591808 (name ?), nlink 3, counted 2
> link count mismatch for inode 3381 (name ?), nlink 2, counted 1
> ...
> block 6/57 type unknown not expected
> block 6/58 type unknown not expected
> block 6/59 type unknown not expected
> ...
> block 6/85154 type unknown not expected
> block 6/85155 type unknown not expected
> block 6/85156 type unknown not expected
> allocated inode 25227791 has 0 link count
> disconnected inode 25166451, nlink 1
> disconnected inode 25166456, nlink 1
> ...
> link count mismatch for inode 29360275 (name ?), nlink 8, counted 7
> link count mismatch for inode 29360282 (name ?), nlink 17, counted 15
> link count mismatch for inode 29360283 (name ?), nlink 2, counted 1
> link count mismatch for inode 30360578 (name ?), nlink 2, counted 1
> link count mismatch for inode 29778244 (name ?), nlink 2, counted 1
>
> Gaspar
>
>