Nikolay Borisov wrote:
On 23.06.20 г. 5:09 ч., Russell Coker wrote:
[395198.926320] BTRFS warning (device sdc1): csum failed root 5 ino 276 off
19267584 csum 0x8941f998 expected csum 0xccd545e0 mirror 1
[395199.147439] BTRFS warning (device sdc1): csum failed root 5 ino 276 off
20611072 csum 0x8941f998 expected csum 0xdaf657cb mirror 1
[395199.183680] BTRFS warning (device sdc1): csum failed root 5 ino 276 off
24190976 csum 0x8941f998 expected csum 0xcddce0b1 mirror 1
[395199.185172] BTRFS warning (device sdc1): csum failed root 5 ino 276 off
19267584 csum 0x8941f998 expected csum 0xccd545e0 mirror 1
[395199.330841] BTRFS warning (device sdc1): csum failed root 5 ino 277 off 0
csum 0x8941f998 expected csum 0xa54d865c mirror 1
I have a USB stick that's corrupted, I get the above kernel messages when I
try to copy files from it. But according to btrfs dev sta it has had 0 read
and 0 corruption errors.
root@xev:/mnt/tmp# btrfs dev sta .
[/dev/sdc1].write_io_errs 0
[/dev/sdc1].read_io_errs 0
[/dev/sdc1].flush_io_errs 0
[/dev/sdc1].corruption_errs 0
[/dev/sdc1].generation_errs 0
root@xev:/mnt/tmp# uname -a
Linux xev 5.6.0-2-amd64 #1 SMP Debian 5.6.14-1 (2020-05-23) x86_64 GNU/Linux
The read/write io err counters are updated when even repair bio have
failed. So in your case you had some checksum errors, but btrfs managed
to repair them by reading from a different mirror. In this case those
aren't really counted as io errs since in the end you did get the
correct data.
I don't think this is what most people expect.
A simple way to solve this could be to put the non-fatal errors in
parentheses if this can be done easily.
For example:
[/dev/sdc1].write_io_errs 0 (5)
IMHO this would be more readable and more useful.
