On Sun, Aug 13, 2017 at 07:12:48PM +0200, Christian Rene Thelen wrote: > I have formated an encrypted disk, containing a LVM with a btrfs system.
What did you format it as? (i.e. what are the locations of the damaged blocks?) > All superblocks appear to be destroyed; the btrfs-progs tools can't > find the root tree anymore and scalpel, binwalk, foremost & co > return only scrap. The filesystem was on an ssd and mounted with -o > compression=lzo. The compression would explain the junk you're getting from the carving tools. They tend to rely on being able to identify sequences of bytes as something recognisable -- compression defeats that by reducing everything to (statistically) random bits. > How screwed am I? Quite badly. > Any chances to recover some files? The compression isn't helping, as noted above. The metadata will be uncompressed, though, so that should be readable, depending on how much was formatted/damaged in the original incident. > Is there a plausible way to rebuild the superblock manually? > Checking the raw image with xxd gives me not a single readable word. That's unsurprising. Metadata isn't human-readable, and nor is compressed data. Did you ever balance this filesystem? More particularly, did you ever balance the metadata? If you did, then there's a good chance it wasn't at the front of the device, and so has a much smaller chance of being damaged. > I managed to decrypt the LV and dd it to an image. What can I do? btrfs-find-root may be able to find some of the tree heads. That at minimum is the information you need in order to reconstruct the superblock (well, that plus the UUID, but the UUID is going to be all over the place -- it shouldn't be hard to find that if the rest is discoverable). That said, recovering this is going to be somewhere between very hard and miraculous. Hugo. -- Hugo Mills | But somewhere along the line, it seems hugo@... carfax.org.uk | That pimp became cool, and punk mainstream. http://carfax.org.uk/ | PGP: E2AB1DE4 | Machinae Supremacy, Rise
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