===== How To Rollover Security Audit Journal File =====

1. Locate and check the size of the current SECURITY.AUDIT$JOURNAL file:

<code>
$ SET DEFAULT SYS$MANAGER
$ DIRECTORY /SIZE /DATE /PROTECTION SECURITY.AUDIT$JOURNAL

Directory SYS$COMMON:[SYSMGR]

SECURITY.AUDIT$JOURNAL;18
                      271030   1-AUG-2018 10:03:56.14  (RWED,RWED,RE,)
SECURITY.AUDIT$JOURNAL;17
                      636538   4-FEB-2018 08:37:07.26  (RWED,RWED,RE,)

Total of 2 files, 907568 blocks.
</code>

2. Create a new version of the SECURITY.AUDIT$JOURNAL logfile:

<code>
$ ! Requires SECURITY, and possibly SYSPRV, privilege:
$ SET PROCESS /PRIVILEGE=(SYSPRV,SECURITY)
$ SET AUDIT /JOURNAL=SECURITY /THRESHOLD=WARN=200  ! resets space-monitoring
$ SET AUDIT /SERVER=NEW_LOG
$ SET PROCESS /PRIVILEGE=(NOSYSPRV,NOSECURITY)
</code>

3. Purge old file versions to free up space -- keep as many recent versions as you like, but consider whether you'll ever actually need to investigate events in those older files (it hardly ever happens, but again, YMMV).

<code>
$ PURGE /KEEP=2 SECURITY.AUDIT$JOURNAL
$ SET PROCESS /PRIVILEGE=(NOSYSPRV,NOSECURITY)
</code>

Of course, you can PURGE /KEEP= any number of versions that you like or need – just don't “keep everything,” as most older versions of this file are just obsolete junk-data (past a certain reasonable “shelf-life”).

If external and/or formal audits are a business requirement, consider archiving older versions of SECURITY.AUDIT$JOURNAL offline (e.g., to tape or nearline SAN storage, etc.) so that date-stamped (historical) versions of the file can be produced for auditing examination and approval.

Done.

==== How Often Should SECURITY.AUDIT$JOURNAL Be Rolled-Over? ====

Different systems and business environments have different operational requirements, but here are a few rules of thumb, and your own specific requirement is likely a combination of two or more of these:

  * Whenever the Security Audit Logfile size gets larger than "a few hundred-MB."
  * Specifically per internal or external/regulatory auditing requirements.
  * Monthly.
  * Quarterly.
  * Maybe even annually.
  * With every system reboot (not suitable for systems which run for months or years without rebooting).