auditd Linux Service

auditd service:

audit daemon. This saves audit records generated by the kernel. It may be useful for servers or machines with multiple users
Now lets see the manual of auditd service.
Manual auditd:
NAME
auditd - The Linux audit daemon
SYNOPSIS
auditd [ -f ]
DESCRIPTION
auditd is the userspace component to the Linux Auditing System. It's responsible for writing audit records to the disk. Viewing the logs is done with the ausearch or aureport utilities. Configuring the audit rules is done with the auditctl utility. During startup, the rules in /etc/audit.rules are read by auditctl. The audit daemon itself has some configuration options that the admin may wish to customize. They are found in the auditd.conf file.
OPTIONS
-f leave the audit daemon in the foreground for debugging. Messages also go to stderr rather than the audit log.
SIGNALS
HUP causes auditd to reconfigure. This means that auditd re-reads the configuration file. If there are no syntax errors, it will proceed to implement the requested changes. If the reconfigure is successful, a DAEMON_CONFIG event is recorded in the logs. If not successful, error handling is controlled by space_left_action, admin_space_left_action, disk_full_action, and disk_error_action parameters in auditd.conf.
TERM caused auditd to discontinue processing audit events, write a shutdown audit event, and exit.
USR1 causes auditd to immediately rotate the logs. It will consult the max_log_size_action to see if it should keep the logs or not.
FILES
/etc/auditd.conf - configuration file for audit daemon
/etc/audit.rules - audit rules to be loaded at startup
NOTES
A boot param of audit=1 should be added to ensure that all processes that run before the audit daemon starts is marked as auditable by the kernel. Not doing that will make a few processes impossible to properly audit.
SEE ALSO
auditd.conf(8), ausearch(8), aureport(8), auditctl(8)