XFS v 1.02 800GB Filesystem problem

[Kevin Giguere <kgiguere@pacbell.net>]

Hello Folks,

I have a filesystem that was acting strangely and I have not been able to
pin point the true cause.
The system was a 1ghz P3, 1 gb ram with external 800GB ide to scsi raid.
The scsi HBA is an adaptec 29160 using the aic78xx driver.

The  filesystem (/dev/sdb1) at its best point would allow me to mount it and
I could view files, however this is all that I could do.  Any attempt to
write a file would freeze the mount and the machine would have to be reset
to free the mount point.  Another raid (/dev/sdc1)in the scsi chain remained
fully usable.

I was able to do an xfs_check /dev/sdb1 and it went straight back to prompt.
No apparent problems.  Restart. Remount. Same behavior; couldn't write
anything...

So I made sure the fs was unmounted and ran xfs_repair -n /dev/sdb1 and a
whole bunch of  errors came up, but it didn't do anything b/c -n option.
Spoke to my Irix guy asking what some of them meant.  We decided to run
xfs_repair and try to fix some of these things.  This produced a message
saying that the log is messed up and I would have to mount to rerun the log.
The new problem was that I could not mount it anymore.  Shutdown checked the
cables, everything was ok.  Other Raid was still fine.  Doesn't look like a
HW problem ( Though I am convinced it is---  SCSI bios looks good,
/proc/scsi/scsi sees everything, /proc/partitions sees everything..but
HMMM).

After wanting to break the thing, I tried again. Same as results as above.
Can't mount if I wanted to, can't run xfs_repair or check.  The only option
to run xfs_repair (and where I am going with this) is xfs_repair -L
/dev/sdb1.  I understood that this is a potentially dangerous option.  But I
didn't have another 800GB volume free to dd onto as b/u.  So I ran this. And
it apparently did a lot.  After this was run, I ran xfs_repair again to
rebuild the log and then mounted.  The great thing is I could mount, read
and write.  The terrible thing is that I couldn't see any data.  All that
was there was an empty lost and found.....,  but xfs_check finds a ton of
mismatches and lost inodes.

As a last ditch I hooked it up to a SGI to see if it could do anything.
>From what I can tell all Irix sees is a raw disk.  I didn't do any fx stuff
fearing ruining any other chances for recovery.

I think that there is very very small chance to get something back, Any one
have any Ideas????

Thanks a million in advance,

Kevin