Quota: Difference between revisions

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In June 2018, we start to enforce disk quota on the [[Multiple Home Directory Servers|new home directory servers]].
In Octobre 2018, we start to enforce disk quota on the 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.
That means you cannot write more data to $HOME than the allotted quotum. The server will act as if your disk is full.
At login time a dialog window will show your current data usage and quota.




'''Q:''' How much quotum do I have?
'''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.
'''A:''' As of Octobre 2018 quota will initially be set to 10 Gb more than your data usage, with a minimum of 50 Gb.




'''Q:''' How much of that is free?
'''Q:''' What if I exceed my quotum?
 
'''A:''' Ask a shell:
quota
It will tell you how much you have, and how much is in use.


'''A:''' A warning dialog will show every 30 minutes, showing the quota information. You will still be able to write to your home directory, as there is a fall-back of 10 Gb extra.


'''Q:''' What if I exceed my quotum?
But when you exceed this fall-back limit (also called "hard limit") your programs won't be able to write anymore and will be in "disk full" condition.


'''A:''' You won't be able to write any more. (But other users still will. That's the point.)
The fall-back of 10 Gb extra also will expire in 7 days after first exceeding the limit. When it expires, "disk full" condition will happen.




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


'''A:''' Either delete some file you do not need anymore, or ask for more space (quotum).  If disk space of the server allows we generally will increase your quotum by return.  However, if you need considerably more than, say 100 Gb, we will ask you apply for a "project directory" and store the bulk of your files there.  See: [[Project Directories]].





Revision as of 15:48, 18 October 2018

In Octobre 2018, we start to enforce disk quota on the 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.

At login time a dialog window will show your current data usage and quota.


Q: How much quotum do I have?

A: As of Octobre 2018 quota will initially be set to 10 Gb more than your data usage, with a minimum of 50 Gb.


Q: What if I exceed my quotum?

A: A warning dialog will show every 30 minutes, showing the quota information. You will still be able to write to your home directory, as there is a fall-back of 10 Gb extra.

But when you exceed this fall-back limit (also called "hard limit") your programs won't be able to write anymore and will be in "disk full" condition.

The fall-back of 10 Gb extra also will expire in 7 days after first exceeding the limit. When it expires, "disk full" condition will happen.


Q: I need more space. What do I do?

A: Either delete some file you do not need anymore, or ask for more space (quotum). If disk space of the server allows we generally will increase your quotum by return. However, if you need considerably more than, say 100 Gb, we will ask you apply for a "project directory" and store the bulk of your files there. 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.