[CentOS] systemd: Failed unmounting /var on reboot, should I worry about fs corruption?

Tue Nov 26 23:50:48 UTC 2019
Ján Lalinský <lalinsky at c4.cz>

Hi all,

I have Centos 8 installed on a physical machine (www6) with separate LVM
volumes for /, /var, /var/lib/mysql etc.

System boot proceeds without a hiccup, in terminal systemctl status says
everything is OK and running, journalctl says so as well - systemd
mounts everything stated in fstab.

However, on reboot systemd echoes problems with filesystem on /var :

...// unmounting all volumes

Nov 26 23:51:30 www6 systemd[1]: Unmounting /var...
Nov 26 23:51:30 www6 umount[2118]: umount: /var: target is busy.
Nov 26 23:51:30 www6 systemd[1]: Stopped target Swap.
Nov 26 23:51:30 www6 systemd[1]: Deactivating swap
/dev/disk/by-label/lv_swap...
Nov 26 23:51:30 www6 systemd[1]: var.mount: Mount process exited,
code=exited status=32
Nov 26 23:51:30 www6 systemd[1]: Failed unmounting /var.

Then proceeds and reboots the machine. This occurs on every reboot.

Did anybody here encounter similar problems on reboot?

I found this bug

https://github.com/systemd/systemd/issues/867

which was closed without a definitive solution, the developer says the
issue is hard to solve and just cosmetic since /var gets unmounted in
the end anyway, which is strange because there is a log line about
unmounting just about every other mountpoint and in the end of the
journal, there are about 7 log lines about unmounting swap volume, but
zilch about /var. If the system is getting down without proper unmount,
data corruption can happen. I would feel much better if there were no
such errors...


My /etc/fstab:

/dev/mapper/vg_www6-lv_root                /               xfs  
defaults,noatime 0  1
/dev/mapper/vg_www6-lv_var                 /var            xfs  
defaults,noatime 0  0
/dev/mapper/vg_www6-lv_swap                swap            swap 
defaults         0  0
/dev/mapper/vg_www6-lv_tmp                 /tmp            xfs  
defaults,noatime 0  0
/dev/mapper/vg_www6-lv_usr_local           /usr/local      xfs  
defaults,noatime 0  0
UUID=XXX                                   /boot           xfs  
defaults         0  0
#/dev/mapper/vg_www6-lv_tmp_mysql          /tmp_mysql      xfs  
defaults,noatime 0  0
tmpfs                                      /tmp_mysql      tmpfs
defaults,noatime,nosuid,nodev,noexec,mode=0755,size=5G 0  0
/dev/mapper/vg_www6-lv_var_lib_mysql       /var/lib/mysql  xfs  
defaults,noatime,uquota,gquota 0  0
/dev/mapper/vg_www6-lv_data                /data           xfs  
defaults,noatime,uquota,gquota 0  0

-- 
S pozdravem
Ján Lalinský

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