In support we see cases from customers regarding log file truncation. One question that commonly comes up is how do you verify log file truncation actually occurs?
The most common method that administrators use when verifying log file truncation post backup is to review the log file directory and note the count of files within this directory. In general, on servers under load that generate a large number of log files in-between backups, this is a safe method to verify log truncation. If there were many logs in the log directory prior to backup and only a few remain post backup, log file truncation would be considered successful.
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