Linux Troubleshooting

SYSLOG

For more insight into the messages you may see in syslog, see the Linux Internals section of this site

less /var/log/syslog

tail -f /var/log/syslog

less /var/log/syslog.1

zless /var/log/syslog.2.gz

view current log

view tail of current log and show new entries as they arrive

view previous log

view compressed previous logs

Ubuntu GUI Frozen

If you are running the Gnome desktop try restarting it.
Press ALT + F2. In the Enter a Command box that appears type r and hit Enter
Or, from a console/terminal prompt...killall -HUP gnome-shell

To force a graceful restart of the system, try this...

Hold down Ctrl + Alt + PrtSc (SysRq) whilst typing r,e,i,s,u,b

"r" Switches the keyboard from raw mode to XLATE mode, "e" Sends the SIGTERM signal to all processes except init, "i" sends the SIGKILL signal to all processes except init, "s" syncs all mounted filesystems, "u" remounts all mounted filesystems in read-only mode, "b" immediately reboot the system, without unmounting partitions or syncing.

Virtual Consoles