The audit trail is contains binary audit files. The trail is created by the auditd daemon. Once the audit service has been enabled with the bsmconv command, the auditd daemon starts when the system is booted. The auditd daemon is responsible for collecting the audit trail data and writing the audit records.
The audit records are stored in binary format on file systems that are dedicated to audit files. Even though you can physically locate audit directories within file systems that are not dedicated to auditing, do not do so except for directories of last resort. Directories of last resort are directories where audit files are written only when no other suitable directory is available.
There is one other scenario where locating audit directories outside of dedicated audit file systems could be acceptable. You might do so in a software development environment where auditing is optional. To make full use of disk space might be more important than to keep an audit trail. However, in a security-conscious environment, the placement of audit directories within other file systems is not acceptable.
You should also consider the following factors when administering audit file systems:
A host should have at least one local audit directory. The local directory can be used as a directory of last resort if the host is unable to communicate with the audit server.
List the audit file systems on the audit server where they reside. The export list should include all systems that are being audited at the site.