Persistent Log Files

The device automatically sends logged system event messages to its storage memory (flash), where they persist even if the device undergoes a reset or powers off. Persistent logging is done by default (and cannot be disabled). Persistent logging eliminates the need for sending logged messages to third-party, logging servers (such as a Syslog server) and provides an efficient tool for troubleshooting the device.

The device can store up to 10 persistent log files. The maximum size (in KB) of each file (default is 1,024 KB) is configured by the following CLI command (or ini file parameter [SystemPersistentLogSize]):

(config-troubleshoot)# syslog
(syslog)# system-persistent-log-size

When the device's persistent logging storage is full, new messages replace the oldest messages (file #9) -- the device deletes the oldest file (#9), creates a new file (#0), and then adds new messages to this new file. The number of all the other files get shifted (i.e., previous #0 becomes #1, previous #1 becomes #2, ... previous #8 becomes #9).

To view a specific persistent log file (0 is the latest), use the following CLI command:

show system log persistent <0-9>