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Guide - How to check BTRFS volume integrity using Monit
Posted: Saturday 19 October 2019 22:44
by ben53252642
A Monit rule and script that does a read only BTRFS file system volume scrub (in this case the root volume / ) at a set time each day and generates a Monit alert if errors were detected.
Rule for /etc/monit/monitrc:
Code: Select all
# BTRFS File System Integrity
check program btrfsintegritycheck with path "/etc/monit/scripts/btrfsintegritycheck.sh"
with timeout 1800 seconds
# Run at 4am each day
every "0 4 * * *"
if status != 0 then alert
Script that goes in:
/etc/monit/scripts/btrfsintegritycheck.sh
Code: Select all
#!/bin/bash
btrfs scrub start -Br / | grep -e 'no errors found' -e 'with 0 errors'
This is an extremely useful tool for detecting for example corruption of an SD card.
Re: Guide - How to check BTRFS volume integrity using Monit
Posted: Monday 04 November 2019 8:05
by ben53252642
Wow! Monit / Mmonit just picked up a server with a corrupt BTRFS volume!
I investigated and sure enough, it was corrupt with unfixable errors, now restoring from a backup.
- monit_btrfs.JPG (342.39 KiB) Viewed 886 times
Checking the server manually (output below):
- btrfs2.JPG (111.72 KiB) Viewed 884 times
Re: Guide - How to check BTRFS volume integrity using Monit
Posted: Friday 08 November 2019 15:21
by ben53252642
I really, really like BTRFS!
Using the below command (will probably vary a bit for different systems), I was able to get a list of files that had become corrupt on the BTRFS file system, delete them (which fixed the file system corruption), then restore just those files that had become corrupted from a backup.
journalctl --output cat | grep 'BTRFS' | grep '(path:' | sed -n -e 's/^.*\(path:\)/\1/p' | cut -f2- -d: | tr -d ")"
Note that I ran this command before the one above: btrfs scrub start -Bd /dev/sda2
Upon deleting the list of corrupt files....
- btrfs5.JPG (57.81 KiB) Viewed 866 times