From: Sebastian Roller <sebastian.roller@gmail.com>
To: Chris Murphy <lists@colorremedies.com>
Cc: Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: All files are damaged after btrfs restore
Date: Fri, 26 Feb 2021 17:01:08 +0100 [thread overview]
Message-ID: <CALS+qHOg89Qtd26NFC4WT+SCv_VxH_k3Erk4=a_pzEMdKZ1Kbw@mail.gmail.com> (raw)
In-Reply-To: <CAJCQCtRkPa7GSjqOBs95ZsJL04o-FBXhgB6xH5KwP+TgupjCnw@mail.gmail.com>
> > I think you best chance is to start out trying to restore from a
> > recent snapshot. As long as the failed controller wasn't writing
> > totally spurious data in random locations, that snapshot should be
> > intact.
>
> i.e. the strategy for this is btrfs restore -r option
>
> That only takes subvolid. You can get a subvolid listing with -l
> option but this doesn't show the subvolume names yet (patch is
> pending)
> https://github.com/kdave/btrfs-progs/issues/289
>
> As an alternative to applying that and building yourself, you can
> approximate it with:
>
> sudo btrfs insp dump-t -t 1 /dev/sda6 | grep -A 1 ROOT_REF
>
> e.g.
> item 9 key (FS_TREE ROOT_REF 631) itemoff 14799 itemsize 26
> root ref key dirid 256 sequence 54 name varlog34
>
Using this command I got a complete list of all the snapshots back to
2016 with full name.
I tried to restore from different snapshots and using btrfs restore -t
from some other older roots.
Unfortunately no matter which root I restore from, the files are
always the same. I selected a list of some larger files, namely ppts
and sgmls from one of our own tools, and restored them from different
roots. Then I compared the files by checksums. They are the same from
all roots I could find the files.
The output of btrfs restore gives me some errors for checksums and
deflate, but most of the files are just listed as restored.
Errors look like this:
Restoring /mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/AWI/AWI_6.14-2_2015.zip
Restoring /mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/AWI/installInstructions.txt
Done searching /Hardware_Software/ABAQUS/AWI
checksum verify failed on 57937054842880 found 000000B6 wanted 00000000
ERROR: lzo decompress failed: -4
Error copying data for
/mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/CM/CMA_win86_32_2012.0928.3/setup.exe
Error searching
/mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/CM/CMA_win86_32_2012.0928.3/setup.exe
ERROR: lzo decompress failed: -4
Error copying data for
/mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/CM/CMAInstaller.msi
ERROR: lzo decompress failed: -4
Error copying data for
/mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/CM/setup.exe
Error searching
/mnt/dumpo/recover/transfer/Hardware_Software/ABAQUS/CM/setup.exe
Most of the files are just listed as "Restoring ...". Still they are
severely damaged afterwards. They seem to contain "holes" filled with
0x00 (this is from some rudimentary hexdump examination of the files.)
Any chance to recover/restore from that? Thanks.
Sebastian
next prev parent reply other threads:[~2021-02-26 16:02 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 15:45 All files are damaged after btrfs restore Sebastian Roller
2021-02-25 5:40 ` Chris Murphy
2021-02-25 5:52 ` Chris Murphy
2021-02-26 16:01 ` Sebastian Roller [this message]
2021-02-27 1:04 ` Chris Murphy
2021-03-04 15:34 ` Sebastian Roller
2021-03-05 3:01 ` Chris Murphy
2021-03-07 13:58 ` Sebastian Roller
2021-03-08 0:56 ` Chris Murphy
2021-03-09 17:02 ` Sebastian Roller
2021-03-09 20:34 ` Chris Murphy
2021-03-16 9:35 ` Sebastian Roller
2021-03-16 19:34 ` Chris Murphy
2021-03-17 1:38 ` Qu Wenruo
2021-03-17 2:59 ` Chris Murphy
2021-03-17 9:01 ` Sebastian Roller
2021-03-17 1:54 ` Dāvis Mosāns
2021-03-17 10:50 ` Sebastian Roller
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