Re: Several unhappy btrfs's after RAID meltdown

["Ryan C. Underwood" <nemesis-lists@icequake.net>]

So, I examined the below filesystem, the one of the two that I would
really like to restore.  There is basically nothing but zeros, and
very occasionally a sparse string of data, until exactly 0x200000
offset, at which point the data is suddenly very packed and looks like
usual compressed data should.  Is there a way one could de-LZO the
data chunkwise and dump to another device so I could even get an idea
what I am looking at?  What about a 'superblock' signature I can scan
for?

> # /usr/local/btrfs-progs/bin/restore -v /dev/mapper/tr5ut-vicep--library /mnt2
> checksum verify failed on 317874630656 wanted 8E19212D found FFFFFFA6
> checksum verify failed on 317874630656 wanted 8E19212D found FFFFFFA6
> checksum verify failed on 317874630656 wanted 491D9C1A found FFFFFFA6
> checksum verify failed on 317874630656 wanted 8E19212D found FFFFFFA6
> Csum didn't match
> restore: root-tree.c:46: btrfs_find_last_root: Assertion
> `!(path->slots[0] == 0)' failed.
> Aborted

-- 
Ryan C. Underwood, <nemesis@icequake.net>