## page was renamed from linux/btrfs/crash202601
= linux/btrfs/crash202601 =

 * My Debian root fs suddenly switched to RO
   * Has root btrfs /dev/sda and /dev/sdb

 * Ran on the system before reboot
   * btrfs check --repair --force /dev/sda

 * Then reboot, booted fine
   * In root terminal ran scub {{{
btrfs scrub start /

watch -d btrfs scrub status -d /
}}}
   * Got this result {{{
UUID:             dd97eb8d-43eb-490e-8ec3-a8bfe58f025e                                       2:29

Scrub device /dev/sdb2 (id 1) status
Scrub started:    Fri Jan  9 00:53:21 2026
Status:           running     history
Duration:         0:07:35
Time left:        finished
ETA:              Fri J40  9 01:01:20 2026
Total to scrub:   215.85GiB
Rate:rected:      480.51MiB/s
Error summary:    csum=16341
  Corrected:      30
  Uncorrectable:  16311
  Unverified:     0

Scrub device /dev/sda2 (id 2) history
Scrub started:    Fri Jan  9 00:53:21 2026
Status:ft:        finished
Duration:         0:07:40
Total to scrub:   215.85GiB
Rate:  cted:      480.51MiB/s
Error summary:    verify=4 csum=16349
  Corrected::     42
  Uncorrectable:  16311
  Unverified:     0

}}}

 * Check disk smart status {{{
apt install smartmontools

root@hp:~# smartctl -H /dev/sda
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.12.57+deb13-amd64] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

root@hp:~# smartctl -H /dev/sdb
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.12.57+deb13-amd64] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

root@hp:~# 

}}}

 * View errors using dmesg/journalctl {{{
sudo journalctl --dmesg --grep 'checksum error'

}}}