xfs data loss

[Passerone, Daniele]

Dear xfs developers

We have a SUN X4500 with 48 500 GB drives, that we configured under SUSE SLES 10.

Among others, we have 3 RAID5 xfs filesystems, /dev/md4 with 20 units (9.27 TB)
/dev/md5 with 20 units (9.27 TB) and /dev/md6 with 5 units (1.95 TB)

These units are not backed up.

Due to a power shock, suddenly and without log messages about one half (5 TB) of the user 
directories on /dev/md4 have disappeared.
Upon reboot, /dev/md6 showed only 3 units, and after a xfs_repair it was again ok.
/dev/md4 mounted immediately, but always with one half of the directories.


1) xfs_check gives no problem on /dev/md4

but 

2) xfs_logprint

xfs_logprint:
    data device: 0x904
    log device: 0x904 daddr: 9279295544 length: 262144

Header 0x1c8b wanted 0xfeedbabe
**********************************************************************
* ERROR: header cycle=7307        block=182240                       *
**********************************************************************
Bad log record header

and the same happens on /dev/md5.


3) xfs_ncheck eats a lot of memory and freezes after 6-7 hours without giving output

4) I have a xfs_metadump in a file (1.8 GB) but I don't know what to do with it.

WHat can I do? Any help would be appreciated, I would really be happy to recover those files...
:-)

Thank you in advance

Daniele Passerone
Empa, Switzerland