UNIX Primer

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Quotas

Since there is a limited amount of space to store data, each user is allotted a maximum amount of space that they are allowed to use. This is called a 'quota.' There is no penalty for using as much space as your quota allows, except that you will be unable to write files that would cause you to exceed your quota.

Therefore, you need to be careful as you near your quota because you can incur some unexpected write errors (ie. you start your homework, work on it for a few hours, finish it off, then it doesn't write because your quota is used up, or you go to read your mail to find out that you are missing mail because there was no room left for it).

When you near your quota limit, you can start cleaning up files on your own as per lesson 8 - cleaning up, or you can run 'raisequota,' which allows you to request an increase in your quota. In either case, it's a good idea to run 'du' first, to figure out which of your directories is taking up the most space.

In rare circumstances, you may need to move part of your quota from your home filesystem to another filesystem (another physical device or partition). A good indicator of this is when you're trying to move a file somewhere and it says that you can't because your quota is exceeded, but you aren't close to exceeding it on your filesystem. The problem is that you have a quota of 0 on the target filesystem. Run 'mvquota' as described below to solve the problem.

The commands below allow you to view, raise and move your quota.

Related Commands:

NamePurpose
quota Shows your quota information.
Syntax
quota -v
Notes
  • You need to be on eniac-l to run this command.

NameMeaningPurpose
du Disk Usage Shows how much space the files in a given directory are currently occupying.
Syntax
du (filename)
Notes
  • Filename is optional. If you don't include one, it uses your current directory as filename.
  • For a full listing of all of your directories, run it on or from your home directory.
  • Otherwise, run it on or from the directory whose size you want to assess.

NamePurpose
raisequota Requests a raise in your quota. Takes you through a clean-up process which attempts to restore some of your space, then asks if you still want to raise your quota. Results are instantaneous.
Syntax
raisequota
Notes
  • You need to be on eniac-l to run this command.
  • There is a maximum number of times you can raise your quota in a given semester. If you still need more space, and have a good reason, you can e-mail manager@cets and request an additional quota increase.

NameMeaningPurpose
mvquota MoVe QUOTA Allows you to move your quota between various filesystems.
Syntax
mvquota <amount> <source_filesystem> <dest_filesystem>
Notes
  • You need to be on eniac-l to run this command.
  • You should not have to use this. It is only mentioned for completeness.


Designed by D. Kaminsky
Edited by Diana Palsetia
© University of Pennsylvania, 2008