Quota

In June 2018, we start to enforce disk quota on the new home directory servers. That means you cannot write more data to $HOME than the allotted quotum. The server will act as if your disk is full.

Q: How much quotum do I have?

A: Usually 50GB. But see the next question. If you had more space in use when we moved you, your quotum is usage + 10GB. But we'll reduce it in the future, as you move stuff to /projects.

Q: How much of that is free?

A: Ask a shell:

quota

It will tell you how much you have, and how much is in use.

Q: What if I exceed my quotum?

A: You won't be able to write any more. (But other users still will. That's the point.)

Q: I need more space. What do I do? A: See Project Directories

Q: I exceeded my quota. All my programs started complaining, and I can't work any more. I can't even log in any more.

A: That's a pity. In the worst case, press <CTR><F2> to get to a text-mode prompt. Log in, and delete some stuff until there is free space. After you logged out, <CTRL><F7> to get back to a graphics mode screen, and perhaps reboot. You should be able to work again.

Q: Quota are a nuisance! Why do we have to have them!?!

A: If large file systems break, fixing them takes weeks. So we want small filesystems. But if one single user writes too much data, all your lwps stop working. And on a small filesystem, the risk is considerable.

Q: Why this artificial split between $HOME and /project?

A: All your programs (shells, editors, browsers, mail, Matlab, etc. etc.) write to $HOME by default. If $HOME is full, all of those break, and some corrupt their data - silently, if you have bad luck. We don't want this for any significant number of users. If /project (or part of it) overflows, only the programs break that were specifically directed to it. That's still bad, but not at all as bad as all your programs failing.