Not a bug: unionfs gets killed when systemd shuts down: "Transport endpoint not connected" errors

[mrvn]

I have a unionfs for / for centos 7 and on shutdown systemd seems to kill the unionfs process near the end. This shows up as a number of "Transport endpoint not connected" errors on the console. After a while the systemd shuts down though so it's not a total showstopper.

I'm writing the pid of the unionfs process into /run/sendsigs.omit.d/unionfs-fuse.pids. But with systemd this does not seem to be sufficient to keep unionfs alive till total shutdown. I'm wondering if you know of something to keep unionfs alive under systemd.