# Introduction The *Troubleshooting Guide* covers the basics of troubleshooting systemd, packages, network interfaces, services such as SSH and Sendmail, the file system, and the Linux kernel. The guide also includes information about the tools that you can use for troubleshooting with examples, how to access the logs, and best practices. - [Systemd and TDNF](systemd-and-tdnf.md) - [The Root Account and the `sudo` and `su` Commands](root-account-sudo-and-su-commands.md) - [Checking the Version and Build Number](checking-the-version-and-build-number.md) - [General Best Practices](general-best-practices.md) - [Photon OS Logs](photon-os-logs.md) - [Troubleshooting Progression](troubleshooting-progression.md)