Hung sessions, missing files or drives
You get the login prompt and your password works, but when you log in your session looks wrong, or hangs, or you can't access files or drives which you usually can. Or you are working happily for a while and then your session freezes or goes wrong.
These glitches can be very annoying, and should be reported to help@maths if they recur. However, isolated problems of this nature can sometimes be resolved without asking for help.
If you are very close to your quota, strange problems may occur because the computer cannot write files when it needs to. Check the quota applet to see if this is your problem, and see the quota page for information on cutting down.
- If you accidentally deleted some files (as opposed to the computer failing to find your home directory / N: drive), see the backup documentation.
- If you're not sure which subdirectory you stored a file in, see the page on locating mislaid files.
Windows
Try pressing Ctrl-Alt-Delete, selecting the Task Manager and killing processes which are not responding. If that doesn't work you'll need to reboot the computer. If you notice that your Windows machine keeps hanging or losing its drives, please report it to help@maths.
Linux
First try rebooting
You can type reboot which will reboot the computer iff nobody else is using it. If this fails or is inconvenient, you may be able to sort out your session without a reboot.
Obtain a working text-based session
- Try to open a terminal window
- Or ssh/putty into the machine
- Or switch to a virtual console
Check files and quota
Type ls. If it fails to show you your files, there is nothing you can do but reboot or ask for help.
If you can see your files, type quota. If you are over your quota, or very close to being over, many strange things can happen as the computer attempts to write to your home directory and finds it can't. Either delete some files or email help@maths for a quota increase.
Kill stuck processes
Now check whether your new text-based session is responding normally. If it is still very slow, the computer is probably "thrashing" i.e. so loaded up with jobs that it is spending all its time working out what to do next and not really achieving very much. Use the top command to check this. Look at the load average and see who is running jobs. If the jobs are not yours, email the user or help@maths (remember to give the name of the overloaded machine).
If your session is mostly OK but one particular window is hung, you can get rid of it by clicking in the top left corner and selecting "Close" from the menu which will appear.
If your whole session is hung, you need to kill the X window manager, which will be xfce4-session for most people. Type
ps uxwww | grep xfce4-session
The first number in the line of output is the process id or "PID" of the process. There may be an extra line for the "grep" command itself - ignore this. Type kill PID, replacing "PID" with the appropriate number, and if this fails then type kill -9 PID which is a more emphatic kill.
