Before starting audit, create a dedicated filesystem for /var/log/audit (minimum 1GB)
Configure grub2 so that processes that are capable of being audited can be audited even if they start up prior to auditd startup
Check if audit is OK at boot
[root@linux01 ~]# grubby --info=ALL | grep -Po '\baudit=1\b' audit=1
Else
[root@linux01 ~]# grubby --update-kernel ALL --args 'audit=1'
During boot if audit=1, then the backlog will hold 64 records. If more that 64 records are created during boot, auditd records will be lost and potential malicious activity could go undetected. Recommended that this value be 8192 or larger.
[root@linux01 ~]# grubby --info=ALL | grep -Po "\baudit_backlog_limit=\d+\b" audit_backlog_limit=<BACKLOG SIZE>
[root@linux01 ~]# grubby --update-kernel ALL --args 'audit_backlog_limit=8192'
Activate auditd service
[root@linux01 ~]# systemctl --now enable audit
Cehck log size and rotation
[root@linux01 ~]# cat /etc/audit/auditd.conf max_log_file = 8 num_logs = 5 ...
List rules
[root@linux01 ~]# auditctl -l No rules
List parameters
[root@linux01 ~]# auditctl -s enabled 1 failure 1 pid 1002 rate_limit 0 backlog_limit 8192 lost 0 backlog 0 backlog_wait_time 60000 backlog_wait_time_actual 0 loginuid_immutable 0 unlocked