The Log Full (Percent) alert provides the percentage of the allowable disk space for the database currently used by the transaction log. Allowable disk space for the database is calculated by taking into account the current allocated space, auto-growth settings and available disk space. If this value exceeds 80%, consider replacing disks with bigger disks.

This alert is raised based on the database metrics collection interval specified in Server Properties. For more information, see Set general server options.

Calculate the log full percentage using the autogrow settings

When setting the thresholds for your Log Full (Percent) alert, click Advanced > Autogrow Settings and SQL Diagnostic Manager provides a choice for you to calculate your displayed percentage. Select Yes, alert on the current used size divided by the maximum possible size to take possible autogrowth into consideration when calculating the log full percentage. Select No, alert on the current used size divided by the current file size to calculate the log full percentage based only on the current size of the database disk file.