Dear Debian users, I am stuck with the following problem which I failed to debug on my Debian 10.3.
In my setup I have /var as mounted volume: === /etc/fatab === UUID=83a3cb60-3334-4d11-9fdf-70b8e8703167 /var btrfs noatime,nodev,nosuid,subvol=var === end === Unfortunately sometimes I notice that binfmt-support is tried to be started "before" /var is mounted. Once I login and restart the service (I don't mount and/or repair anything), it starts just fine. === console === root@debian:~ # systemctl status binfmt-support * binfmt-support.service - Enable support for additional executable binary formats Loaded: loaded (/lib/systemd/system/binfmt-support.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Sun 2020-05-10 21:54:27 CEST; 10h ago Docs: man:update-binfmts(8) Process: 353 ExecStart=/usr/sbin/update-binfmts --enable (code=exited, status=2) Main PID: 353 (code=exited, status=2) May 10 21:54:27 debian update-binfmts[353]: update-binfmts: unable to open /var/lib/binfmts: No such file or directory root@debian:~ # ll /var/lib/binfmts total 16 drwxr-xr-x 1 root root 50 Mar 17 23:46 . drwxr-xr-x 1 root root 988 Mar 2 01:57 .. -rw-r--r-- 1 root root 49 Apr 14 2019 jar -rw-r--r-- 1 root root 59 Mar 17 23:46 python3.7 root@debian:~ # systemctl start binfmt-support root@debian:~ # systemctl status binfmt-support * binfmt-support.service - Enable support for additional executable binary formats Loaded: loaded (/lib/systemd/system/binfmt-support.service; enabled; vendor preset: enabled) Active: active (exited) since Mon 2020-05-11 09:01:04 CEST; 4s ago Docs: man:update-binfmts(8) Process: 9683 ExecStart=/usr/sbin/update-binfmts --enable (code=exited, status=0/SUCCESS) Main PID: 9683 (code=exited, status=0/SUCCESS) May 11 09:01:04 debian systemd[1]: Starting Enable support for additional executable binary formats... May 11 09:01:04 debian systemd[1]: Started Enable support for additional executable binary formats. root@debian:~ # dpkg -l | grep -i systemd ii systemd 241-7~deb10u3 amd64 system and service manager ... === end === One time the system was started with even more units failed because of inaccessible /var. There is nothing special in these units, and I haven't modified any *.service files. In other words the problem is floating, as number of failed unit varies from boot to boot. The difficulty is that I don't know how to debug system start / systemd at such early stage of system boot. Any help is appreciated. -- With best regards, Dmitry