<<That's not expected. I was rather expecting maybe 5 lines, all within
a 1MiB range.
I'm pretty sure, but not absolutely sure, that LVM metadata is in the
first 1MiB. And yet in your first 1MiB that was supposedly zero'd,
there's a bogus GPT (header only), and a btrfs signature, and that
doesn't pass the smell test. Something is missing about our
understanding of how all of this is supposed to be assembled. I'll
have to think about the proper questions to even ask next.>>
Chris,
I had Synology look at the enclosure and they reported:
"
Our developers have looked into this, and they were able to fix the
corrupted LVM metadata.
Unfortunately, it looks like the dd operation corrupted the Btrfs root
tree, too. The root tree is the entrance of your filesystem and tells
the Btrfs module where to find all the other trees--the filesystem
tree that contains the directory structure, the device tree that tells
Btrfs what block devices are part of the filesystem, the checksum tree
that stores the checksums for everything else, etc. I tried as many
different alternate root trees as I could to correct the issue, but
every attempt was unsuccessful.
When this happens, our next step is to scan the volume for additional
roots to see if it's possible to restore the contents of your volume
to external storage. However, when I performed a dry run, the results
indicated that the operation completely failed and could not
successfully restore any data. As a last ditch measure I tried to pull
the subvolume ID of your shared folders so we could look into
restoring each folder individually, but this failed as well.
At this point, there are unfortunately no further steps that we can
take to try and recover your data. You can perhaps try consulting with
the official Btrfs mailing list to see if they can provide any further
guidance.
"
I've replied with the following request:
"
Can you provide details as to how the sinology nas sets this up with
LVM and BTFS? Specifically; the Linux mail list was unable to
determine how the partitions interrelate and how they might be mapped
to the logical volumes.
Is it possible that any of the roots might be available on the
untouched physical disk 3? This disk was not present in the enclosure
when the dd was preformed.
"
but I'm honestly a little lost as to what specifically to ask. Have
you been able to formulate any specific questions I should ask them?
John
