+USERS AND GROUPS:
+ Default udev rules use the following standard system group
+ names, which need to be resolvable by getgrnam() at any time,
+ even in the very early boot stages, where no other databases
+ and network are available:
+
+ audio, cdrom, dialout, disk, input, kmem, lp, tape, tty, video
+
+ During runtime, the journal daemon requires the
+ "systemd-journal" system group to exist. New journal files will
+ be readable by this group (but not writable), which may be used
+ to grant specific users read access. In addition, system
+ groups "wheel" and "adm" will be given read-only access to
+ journal files using systemd-tmpfiles.service.
+
+ The journal gateway daemon requires the
+ "systemd-journal-gateway" system user and group to
+ exist. During execution this network facing service will drop
+ privileges and assume this uid/gid for security reasons.
+
+ Similarly, the NTP daemon requires the "systemd-timesync" system
+ user and group to exist.
+
+ Similarly, the network management daemon requires the
+ "systemd-network" system user and group to exist.
+
+ Similarly, the name resolution daemon requires the
+ "systemd-resolve" system user and group to exist.
+
+ Similarly, the kdbus dbus1 proxy daemon requires the
+ "systemd-bus-proxy" system user and group to exist.
+
+NSS:
+ systemd ships with three NSS modules:
+
+ nss-myhostname resolves the local hostname to locally
+ configured IP addresses, as well as "localhost" to
+ 127.0.0.1/::1.
+
+ nss-resolve enables DNS resolution via the systemd-resolved
+ DNS/LLMNR caching stub resolver "systemd-resolved".
+
+ nss-mymachines enables resolution of all local containers
+ registered with machined to their respective IP addresses.
+
+ To make use of these NSS modules, please add them to the
+ "hosts: " line in /etc/nsswitch.conf. The "resolve" module
+ should replace the glibc "dns" module in this file.
+
+ The three modules should be used in the following order:
+
+ hosts: files mymachines resolve myhostname
+