SYSTEMD-JOURNALD.SERVICE(8) systemd-journald.service (NAME) systemd-journald.service, systemd-journald.socket, systemd-journald- dev-log.socket, systemd-journald-audit.socket, systemd- journald@.service, systemd-journald@.socket, systemd-journald- varlink@.socket, systemd-journald - (SYNOPSIS) systemd-journald.service systemd-journald.socket systemd-journald-dev-log.socket systemd-journald-audit.socket systemd-journald@.service systemd-journald@.socket systemd-journald-varlink@.socket /usr/lib/systemd/systemd-journald (DESCRIPTION) systemd-journald . : o kmsg o syslog(3) libc o (native Journal API) sd_journal_print(3) Native Journal Protocol[1] o . . o . systemd.journal-fields(7) . . 2-1 . /var/log/journal /run/log/journal/ ( ). /var/log/journal/ . Storage= journald.conf(5) /var/log/journal/ . journald journalctl --flush ( SIGUSR1 journald) ( ). "systemd-journal-flush.service" . /var/log/journal/ ( journald.conf ) : mkdir -p /var/log/journal systemd-tmpfiles --create --prefix /var/log/journal journald.conf(5) . (STREAM LOGGING) systemd . StandardOutput=/StandardError= systemd.exec(5) . ("\n" 10) NUL . systemd-journald.service . EPIPE . / . SIGPIPE signal(7) . systemd SIGPIPE ( IgnoreSIGPIPE= systemd.exec(5) ). / . systemd-journald.service (file descriptors) . systemd-journald.service systemctl restart systemctl stop systemctl start ( ) . systemd-journald.service . / (peer) . ( ) . . / systemd- cat(1) . systemd-journald . EPIPE . (JOURNAL NAMESPACES) << >> . systemd-journald . IPC . systemd-journald.service ( ) . systemd-journald@.service . . LogNamespace= systemd.exec(5) . --namespace= journalctl(1) . . syslog(3) / . . systemd-journald /etc/systemd/journald.conf ( ) /etc/systemd/journald@NAMESPACE.conf . /var/log/journal/MACHINE_ID ( ) /var/log/journal/MACHINE_ID.NAMESPACE . (SIGNALS) SIGUSR1 (flush) /run/ /var/ ( ). (mount) /var/ /run/ /var/ . journalctl --flush . journalctl(1) . 186. SIGUSR2 . journalctl --rotate . 186. SIGRTMIN+1 . journalctl --sync . 228. SIGHUP SIGHUP systemd-journald . ReadKmsg= . ( ) . . 258. (CREDENTIALS) systemd-journald ImportCredential=/LoadCredential=/SetCredential= ( systemd.exec(5) ). : journal.forward_to_socket . ForwardToSocket= journald.conf(5) . 256. journal.storage . Storage= journald.conf(5) . 256. (KERNEL COMMAND LINE) journald.conf : systemd.journald.forward_to_syslog=, systemd.journald.forward_to_kmsg=, systemd.journald.forward_to_console=, systemd.journald.forward_to_wall= syslog wall / . journald.conf(5) . 186. systemd.journald.max_level_store=, systemd.journald.max_level_syslog=, systemd.journald.max_level_kmsg=, systemd.journald.max_level_console=, systemd.journald.max_level_wall=, systemd.journald.max_level_socket= syslog(3) kmsg wall(1) . journald.conf(5) . 232. . (ACCESS CONTROL) "systemd-journal" . . UID nobody /var/log/journal/ . UID Users, Groups, UIDs and GIDs on systemd systems[2] . . (ACL) . (ACL) . "wheel" "adm" : # setfacl -Rnm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/ ACL /var/log/journal/ . (FILES) /etc/systemd/journald.conf systemd-journald. journald.conf(5) . 206. /run/log/journal/machine-id/*.journal, /run/log/journal/machine-id/*.journal~, /var/log/journal/machine-id/*.journal, /var/log/journal/machine-id/*.journal~ systemd-journald /run/log/journal/machine-id/ /var/log/journal/machine-id/ ".journal" . ".journal~" systemd-journald . /run/ /var/log/journal Storage=volatile journald.conf(5) . systemd-journald "original-name@suffix.journal" ( "original-name@suffix.journal~") . <<>> . ( ) . journalctl(1) sd-journal(3) . systemd-journald . SystemMaxUse= journald.conf(5) . 206. /dev/kmsg, /dev/log, /run/systemd/journal/dev-log, /run/systemd/journal/socket, /run/systemd/journal/stdout systemd-journald . systemd-journald "systemd-journald-audit.socket" netlink(7) . 228. . (SEE ALSO) systemd(1), journalctl(1), journald.conf(5), systemd.journal-fields(7), sd-journal(3), systemd-coredump(8), setfacl(1), sd_journal_print(3), pydoc systemd.journal (NOTES) 1. Native Journal Protocol https://systemd.io/JOURNAL_NATIVE_PROTOCOL 2. Users, Groups, UIDs and GIDs on systemd systems https://systemd.io/UIDS-GIDS systemd 261.2 SYSTEMD-JOURNALD.SERVICE(8)