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/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, last -f /var/log/btmp | more |
/var/log/cl-system-services.log | Information about system services, such as switchd. |
/var/log/crit.log | Log messages with a critical severity level. |
csmgrd.log | ISSU errors and information. |
/var/log/dpkg.log | Information that the system logs when you install or remove a package with the dpkg command. |
/var/log/frr/* | Troubleshoots routing (FRR), such as an MD5 or MTU mismatch with OSPF. |
ifupdown2 | Information that the system logs from the network interface manager (ifupdown2). |
/var/log/installer/* | Information about Cumulus Linux installation. |
/var/log/lastlog | Formats and prints the contents of the last login log file. |
/var/log/lttng-traces | Information about LTTng sessions. |
mstpd | Spanning Tree Protocol service errors and information. |
/var/log/netqd.log | Information about the NetQ agent. |
/var/log/nginx | Errors and processed requests in NGINX. |
/var/log/nv-cli.log | Information about the NVUE CLI. |
/var/log/ntpstats | Logs for network configuration protocol. |
/var/log/nvued.log | Log file for NVUE. |
/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. |