Zbigniew Jędrzejewski-Szmek (zbyszek(a)in.waw.pl) said:
Splitting is controlled by SplitMode=
Controls whether to split up journal files per user. One of "login",
"uid" and "none". If "login" each logged in user will get
his own
journal files, but systemd user IDs will log into the system
journal. If "uid" any user ID will get his own journal files
regardless whether it belongs to a system service or refers to a
real logged in user. If "none" journal files are not split up
per-user and all messages are stored in the single system journal. [1]
I guess this could be sanely extended to split the logs for some services
out even more.
Presumably you'd want to do them by either service name or by slice?
Bill