Backup and Clear Domain Controller Security Event Logs

A post related to, for Case 3.

If you don’t manage security logs by regularly backing them up and clearing them, you risk losing important historical information. Additionally, running a LogParser query against a large, unmanaged security event log takes a long time.

The below script is designed to be run daily at the end of the day to backup the security event log on a Domain Controller and then clear its contents. Additionally, the logs are archived off to two windows shares to allow for long term storage.

The script makes use of Jaap Brasser’s DeleteOld script ( to carry out tidy up operations of the local staging folder. In practice, I used the same script to manage the archive folders too, keeping 365 days worth of logs.

Usage: .\BACKUP_AND_CLEAR_EVENTLOGS.ps1 <DomainController> $clear

Make sure that the security event log maximum size is increased to a high enough level to ensure that none of the days logs get overwritten. Judging that size will depend on the number of events per day or alternatively just set to “do not overwrite events”.

Note: the event ID’s are purely made up 😉