Terminal logging

Many customers do not have a console port connected to the units and therefore cannot monitor any debug or error messages that are shown on the console. For example, in a stacking environment where the console and management port is connected only to an active unit, the user cannot access or monitor any debug or error messages generated on the system from the member units, standby units, or PE units.

Terminal logging, which is enabled by default, captures all the console messages generated on the system to a RAMFS file, and copies the RAMFS file to the flash memory upon certain triggers. Logs from Telnet and SSH sessions are also logged to the file. Each unit in the stack (active, standby, or member unit) has corresponding log files created if terminal logging is enabled. Apart from the console prints which are stored in the ss_console.txt file, terminal logging also logs dmesg output (Linux kernel log) in the kmsg.txt file and copies it to flash memory. The logging files are stored in the /fast_iron/logs folder. The log files copied to the flash memory can be retrieved later using supportsave for offline debugging and analysis.

The following triggers copy both the FastIron terminal logging files and Linux dmesg to the flash memory.

  • Booting the system from the primary partition.
  • Booting the system from the secondary partition.
  • Issuing a reload of the entire stack.
  • Issuing a reload of a particular unit (standby, member, or PE).
  • FastIron crash
  • Watchdog timeout

Terminal logging limitations

The following limitations apply to terminal logging:

  • The file size is limited to 10 MB after which the prints wrap over.
  • Uboot logs are not logged.
  • SIL logs are not logged.
  • SIM logs are not logged.
  • If the user switches to the OS prompt, then OS logs are not logged.

In this section:

  1. Enabling terminal logging
Parent topic: Configuration Fundamentals