Whatever it is, I have yet to identify a problem from it not having started. But my antiX installation has complained about it for a long time.console login message wrote: [ 341.228842] systemd-logind[2716]: Failed to start user service: Unknown unit: user@1004.service
I also run Opensuse and Mageia linux with as close to the same set up as I can manage. But it's only the antiX that gives me this warning. And lately I've been booting to antiX, often enough for it to bug me.
I'm suspicious that it has something to do with booting to runlevel3, and using startx when/if ready to put up with a gui. (Though I'll admit that 95% of the time, startx is my first user command upon logging in to a tty.) But I don't really know what it is.
By the way, if the text of the warning message didn't make it clear,"1004" is my regular user account's UID.
Anybody have a clue what it's talking about?