Re: btrfs check Causes File Corruption
>Why not btrfs check?
'btrfs check' also reported a checksum error.
>As already suggested, you might do better looking elsewhere for help.
>Perhaps the linux-btrfs mailing list?
Thank you for your suggestion, I am preparing to seek help from linux-btrfs mailing list.
On August 20, 2023 12:54:01 PM UTC, debian-user@howorth.org.uk wrote:
>"Longhao.Chen" <Longhao.Chen@outlook.com> wrote:
>> Hello everyone, I use Btrfs as the file system on my laptop.
>> Yesterday, I was preparing to backup a snapshot to an external hard
>> drive using btrfs send, and the following error occurred:
>>
>> ERROR: send ioctl failed with -5: Input/Output error
>
>I use btrfs but don't know much about it :( I certainly know nothing
>about btrfs send, but the error seems to suggest perhaps an error with
>the send rather than with reading the source?
>
>> I used btrfs scrub to scan the disk, and the result was:
>
>Why not btrfs check?
>
>> Error summary: csum=1
>>
>> Corrected: 0
>>
>> Uncorrectable: 1
>>
>> Unverified: 0
>
>OK so that sounds like a hardware problem.
>
>> Afterwards, I booted a LiveCD and ran:
>>
>> btrfs check --init-csum-tree
>>
>> During the running process, many outputs similar to this appeared:
>>
>> root 1380 inode 5006723 errors 2001, no inode item, link count wrong
>> unresolved ref dir 1164151 index 1566 namelen 28 name <filename>
>> filetype 1 errors 4, no inode ref
>>
>> Then I found that the file in the above <filename> had disappeared.
>> At this point, I immediately backed up all the existing files and
>> then used:
>>
>> btrfs check --repair
>>
>> btrfs rescue
>>
>> in an attempt to recover the lost files, but was unsuccessful.
>>
>> The current issues are:
>>
>> How do I recover the lost files?
>
>From a backup? I think they're gone from the source. (But what do I
>know)
>
>> Why does btrfs check --init-csum-tree cause file loss? Is this a bug?
>
>Seems unlikely. Why do you think the command causes the file loss? Why
>do you not think the corruption was already there? And did you read the
>DANGEROUS description in the docs?
>
>> LiveCD information:
>>
>> Linux ubuntu 6.2.0-26-generic #26~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC
>> Thu Jul 13 16:27:29 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
>>
>> Thank you for your help.
>
>As already suggested, you might do better looking elsewhere for help.
>Perhaps the linux-btrfs mailing list?
>
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