When a log file reaches it maximum size, the log file is backed up by adding the number 1 after its file name extension and a new log file is created. The extension numbering of any exising backup files are incremented sequentially. For example, when dbs.log reaches it maximum size, it is renamed to dbs.log.1; the file dbs.log.1 is renamed to dbs.log.2, and so on, up to the maximum number of log files configured (the default setting is 13).
When the maximum number of files is reached, the oldest file is deleted.
Sensor log file size and maximum number of log files are configured on the Sensor properties page in the management console.