Hi, Boris Burkov, Chris Murphy
This happened is my server too.
1, this warning [*1] is not loged in /var/log/messages
because it happened after the ro remount of /
my server is a dell PowerEdge T640, this log can be confirmed by
iDRAC console.
[*1] BTRFS warning (device vda3): remount supports changing free space
tree only from ro to rw
2, no space_cache=v2 in /etc/fstab
but space_cache=v2 is reported in /proc/mounts
systemd-shutdown ro remount / with the param based on /proc/mount
Best Regards
Wang Yugui (wangyu...@e16-tech.com)
2021/02/21
> Hi,
>
> systemd does remount ro at reboot/shutdown time, and if free space
> tree exists, this is always logged:
>
> [ 27.476941] systemd-shutdown[1]: Unmounting file systems.
> [ 27.479756] [1601]: Remounting '/' read-only in with options
> 'seclabel,compress=zstd:1,space_cache=v2,subvolid=258,subvol=/root'.
> [ 27.489196] BTRFS info (device vda3): using free space tree
> [ 27.492009] BTRFS warning (device vda3): remount supports changing
> free space tree only from ro to rw
>
> Is there a way to better detect that this isn't an attempt to change
> to v2? If there's no v1 present, it's not a change.
>
> --
> Chris Murphy
