Audit logs are stored in the /var/log/audit directory.
Ensure that /var/log/audit has its own partition or logical
volume at installation time, or migrate it using LVM.
Make absolutely certain that it is large enough to store all
audit logs that will be created by the auditing daemon.
Rationale
Placing /var/log/audit in its own partition
enables better separation between audit files
and other files, and helps ensure that
auditing cannot be halted due to the partition running out
of space.
ISA-62443-2-1-2009, Security for Industrial Automation and Control Systems Part 2-1: Establishing an Industrial Automation and Control Systems Security Program