The journal configuration file is located at /etc/systemd/journald.conf. Following is an example of the beginning of the journald configuration file.

[Journal]
#Storage=auto
#Compress=yes
#Seal=yes
#SplitMode=uid
#SyncIntervalSec=5m
#RateLimitInterval=30s
. . .

Storage

When the Storage option is commented out, the journal messages will be written to a file in the /run/log/journal directory. This file is not permanent - the file is erased when the system is shutdown or restarted. Uncommenting Storage will configure the journal to write messages to a file in the /var/log/journal directory. The four storage options are:

• auto - you need to create the /var/log/journal directory, and give the directory the appropriate owner and permissions.
• persistent - the /var/log/journal directory will automatically be created if it does not exist.
• volatile - similar to commenting out Storage. Messages will be written to a file in the /run/log/journal directory.
• none - discard all messages

Compression

Uncommenting compress will compress the journal using xz compression. There are 6 options to control the size of the journal. The 3 options that start with "System" are used to control the size of the journal at /var/log/journal. The 3 options that start with "Runtime" are used to control the size of the journal at /run/log/journal.

• SystemMaxUser=10%
• SystemKeepFree=15%
• SystemMaxFileSize=240M
• RuntimeMaxUse=10%
• RuntimeKeepFree=15%
• RuntimeMaxFileSize=240M

MaxFileSec=1month means that the journal will retain messages for 1 month before purging the messages.

ForwardToSyslog=yes tells the journal to share messages with syslogd, rsyslogd, and syslog-ng.

Forward toKMsg=yes tell the journal to share messages with klogd.