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Set the size of the Windows event log
To ensure that you don't "lose" any events, you must configure the maximum size for security event logs appropriately. For audit policy settings the storage requirements is roughly 1KB per event.
For a server outage or maintenance time (of the collector server selected for the AD Logga) of one hour, with approximately 1000 events per hour, the absolute minimum security event log size would be 1MB. Considering the low storage space requirements for 1000 events, the uncertainty of outage times as well as the potential relevance of individual security events we highly recommend that you ensure that enough storage space is available.
More information on how to manage storage size can be found at Microsoft.