This document describes how to enable system logging messages in order to save output to the router's flash disk.
Logging messages to an internal buffer must be enabled using logging buffered Command Line Interface (CLI)
Enough free space on the flash disk in order to store the desired number of logging files
Note: It is recommended to set the system clock to the correct date and time and verify router’s Central Processing Unit (CPU) utilization before and after feature activation.
This document is not restricted to any specific software and hardware versions.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Typically, logging messages (warnings, error and/or debugs etc.) are stored in a router's memory buffer (DRAM); when the buffer is full, older messages are overwritten by new messages. This poses an issue when trying to capture debugs for an intermittent issue or during high traffic. Huge buffer size configuration can not alwayshelp as the buffer can get filled and overwritten quickly during verbose debugging. Using persistent logging allows to write logged messages to file(s) on router's flash disk. The advantage is unlike memory buffer (DRAM) contents these files persist when the router reboots (DRAM contents are erased during a reboot.)
Step 1. Enable system logging message to a local buffer:
Step 2. Enable logging messages in order to write from the memory buffer to router's flash disk: