If you are using the current version of Cumulus Linux, the content on this page may not be up to date. The current version of the documentation is available here. If you are redirected to the main page of the user guide, then this page may have been renamed; please search for it there.

Troubleshooting Log Files

The only real unique entity for logging on Cumulus Linux compared to any other Linux distribution is switchd.log, which logs the HAL (hardware abstraction layer) from hardware.

Read this guide on NixCraft to understand how /var/log works.

Log File Descriptions

Log Description
/var/log/alternatives.log Information from update-alternatives.
/var/log/apt Information from the apt utility. For example, from apt-get install and apt-get remove.
/var/log/audit/* Information stored by the Linux audit daemon, auditd.
/var/log/autoprovision Output generated by running the zero touch provisioning script (ZTP).
/var/log/boot.log Information that the system logs when the switch boots.
/var/log/btmp Information about failed login attempts. Use the last command to view the btmp file. For example:
cumulus@switch:~$ last -f /var/log/btmp | more
/var/log/clagd.log Status of the clagd service.
/var/log/dpkg.log Information that the system logs when you install or remove a package with the dpkg command.
/var/log/frr/* FRR - Used to troubleshoots routing, such as an MD5 or MTU mismatch with OSPF.
/var/log/gunicorn Error and access events in Gunicorn.
/var/log/installer/* Directory containing files related to the installation of Cumulus Linux.
/var/log/lastlog Formats and prints the contents of the last login log file.
/var/log/nvued.log Log file for NVUE.
/var/log/nginx Errors and processed requests in NGINX.
/var/log/ntpstats Logs for network configuration protocol.
/var/log/openvswitch/* ovsdb-server logs.
/var/log/ptmd Prescriptive Topology Manager (PTM) errors and information.
/var/log/switchd.log The HAL log for Cumulus Linux.
This is specific to Cumulus Linux. The system logs switchd crashes here.
/var/log/syslog The main system log, which logs everything except auth-related messages.
The primary log; grep this file to see what problem occurred.
/var/log/wtmp Login records file.