Troubleshooting

The following sections cover various troubleshooting information which may be helpful when diagnosing installation issues.

Consoles and logging during installation

The CentOS installer uses the tmux terminal multiplexer to display and control several windows you can use in addition to the main interface. Each of these windows serves a different purpose - they display several different logs, which can be used to troubleshoot any issues during the installation, and one of the windows provides an interactive shell prompt with root privileges, unless this prompt was specifically disabled using a boot option or a Kickstart command.

In general, there is no reason to leave the default graphical installation environment unless you need to diagnose an installation problem.

The terminal multiplexer is running in virtual console 1. To switch from the actual installation environment to tmux, press Ctrl+Alt+F1. To go back to the main installation interface which runs in virtual console 6, press Ctrl+Alt+F6.

If you choose text mode installation, you will start in virtual console 1 (tmux), and switching to console 6 will open a shell prompt instead of a graphical interface.

The console running tmux has 5 available windows; their contents are described in the table below, along with keyboard shortcuts used to access them. Note that the keyboard shortcuts are two-part: first press Ctrl+b, then release both keys, and press the number key for the window you want to use.

You can also use Ctrl+b n and Ctrl+b p to switch to the next or previous tmux window, respectively.

Table 1. Available tmux windows
Shortcut	Contents
`Ctrl`+`b` `1`	Main installation program window. Contains text-based prompts (during text mode installation or if you use VNC direct mode), and also some debugging information.
`Ctrl`+`b` `2`	Interactive shell prompt with `root` privileges.
`Ctrl`+`b` `3`	Installation log; displays messages stored in `/tmp/anaconda.log`.
`Ctrl`+`b` `4`	Storage log; displays messages related to storage devices from kernel and system services, stored in `/tmp/storage.log`.
`Ctrl`+`b` `5`	Program log; displays messages from other system utilities, stored in `/tmp/program.log`.

Saving screenshots

You can press Shift+Print Screen at any time during the graphical installation to capture the current screen. These screenshots are saved to /tmp/anaconda-screenshots.