Sometimes I boot up to a blank screen. Sometimes it works just fine

[megavolt]

@cscs

System Logs ( dmesg , journalctl , /var/log/ )

These commands can be used to find errors and troubleshoot

• dmesg

This command is used to get examine kernel ring buffer logs like hardware errors.

Use examples:

$ sudo dmesg | less

Pipe command to less so output is scrollable with arrow keys.

$ sudo dmesg | grep usb

Get info on usb devices

$ sudo dmesg -l emerg,alert,crit,err,warn

Print only emergency, alert, critical, error, warn messages.

• journalctl

This command is used to query the (systemd) journal logs, as documented here .

Use examples:

$ journalctl -x -p3 -b1

The flags correspond to explanatory output, priority level, and which boot to pull logs from.

journalctl -f

Live printing of the journal.

• /var/log/

This directory can contain logs from a number of sources.

Use examples:

$ cat /var/log/Xorg.0.log

Print Xorg log from the current session.

$ cat /var/log/Xorg.0.log.old

Print Xorg log from the previous successful session.

$ cat /var/log/Xorg.1.log

You could start here.