Common Log Files for Troubleshooting

This page provides a comprehensive list of important log file paths in Ubuntu Server environments commonly used at Voltage Park. From system logs to application-specific logs, understanding where and

Log Type	Log Path
System Log	/var/log/syslog
Kernel Log	/var/log/kern.log
Boot Log (dmesg)	/var/log/dmesg
Authentication Log	/var/log/auth.log
NVIDIA Installer Log	/var/log/nvidia-installer.log
Slurm Controller Log	/var/log/slurm/slurmctld.log
Slurm Node Daemon Log	/var/log/slurm/slurmd.log
Docker Log	/var/log/docker.log
NFS Logs	/var/log/messages, /var/log/syslog
NGINX Access Log	/var/log/nginx/access.log
NGINX Error Log	/var/log/nginx/error.log
Apache Access Log	/var/log/apache2/access.log
Apache Error Log	/var/log/apache2/error.log
MySQL / MariaDB Error Log	/var/log/mysql/error.log
PostgreSQL Log	/var/log/postgresql/postgresql-<version>-main.log
UFW Log	/var/log/ufw.log
Fail2Ban Log	/var/log/fail2ban.log
APT History Log	/var/log/apt/history.log

How to Access and Read Log Files

Logs are essential for troubleshooting issues in a server environment. You can access log files using the command line in Ubuntu. Most of these logs are located in the /var/log/ directory. Below are a few common commands to access and read log files:

• View Logs in Real-Time: Use tail -f to follow the most recent updates in a log file:

  sudo tail -f /var/log/syslog

• View Entire Log File: Use cat to display the entire contents of a log file:

  sudo cat /var/log/kern.log

• Search for Specific Terms: Use grep to filter log entries for a specific keyword:

  sudo grep "error" /var/log/syslog

• View Compressed Logs: Archived logs are often compressed with .gz. You can use zcat to read them (may need installing with apt-get install:

  sudo zcat /var/log/syslog.1.gz