mai 04 18:10:44 sharu kernel: BTRFS info (device sdb1): bdev /dev/sdc1 errs: wr 0, rd 2, flush 0, corrupt 0, gen 0
Ma config btrfs utilise 2 disques de 2To en RAID 1. D'après ce que j'ai compris une erreur en lecture est une section d'un disque dur qui aurait une somme de contrôle ne correspondrait pas à celle de l'autre disque dur. Je ne sais pas trop si j'ai bien compris la situation ni comment m'y prendre à ce stade pour corriger ça
$ sudo btrfs scrub status /dev/sdb1
scrub status for 4fbdc6db-c13c-4f61-8e46-fe117dd24b79
scrub started at Fri May 4 18:25:10 2018, running for 00:05:01
total bytes scrubbed: 54.31GiB with 0 errors
$ sudo btrfs scrub status /dev/sdb1
scrub status for 4fbdc6db-c13c-4f61-8e46-fe117dd24b79
scrub started at Fri May 4 18:25:10 2018 and finished after 00:57:42
total bytes scrubbed: 602.31GiB with 0 errors
$ man btrfs-scrub | grep repa
btrfs scrub is used to scrub a btrfs filesystem, which will read all data and metadata blocks from all devices and verify checksums. Automatically repair corrupted blocks if there’s a correct copy
Scrub is not a filesystem checker (fsck) and does not verify nor repair structural damage in the filesystem.
DEVICE STATS
The device stats keep persistent record of several error classes related to doing IO. The current values are printed at mount time and updated during filesystem lifetime or from a scrub run.
$ btrfs device stats /dev/sda3
[/dev/sda3].write_io_errs 0
[/dev/sda3].read_io_errs 0
[/dev/sda3].flush_io_errs 0
[/dev/sda3].corruption_errs 0
[/dev/sda3].generation_errs 0
write_io_errs
Failed writes to the block devices, means that the layers beneath the filesystem were not able to satisfy the write request.
read_io_errors
Read request analogy to write_io_errs.
flush_io_errs
Number of failed writes with the FLUSH flag set. The flushing is a method of forcing a particular order between write requests and is crucial for implementing crash consistency. In case of
btrfs, all the metadata blocks must be permanently stored on the block device before the superblock is written.
corruption_errs
A block checksum mismatched or a corrupted metadata header was found.
generation_errs
The block generation does not match the expected value (eg. stored in the parent node).
en RAID 1, btrfs ferait de l'auto-correction à chaud à partir du data block dont la somme de contrôle est OK, si j'ai bien compris