The quotas(4) Subsystem

In general, it is your job as the site administrator to set disk use policies, establishing and enforcing quotas if necessary. You should publish clear guidelines for disk use, and notify users who regularly exceed their quotas. It is also a good idea to impose quotas on the use of temporary directories, such as /tmp and on all anonymous ''guest'' accounts, such as guest and uucp. If your root file system reaches 100% capacity, your system may shut down and inconvenience your users.

You should be as flexible as possible with disk quotas. Often, legitimate work forces users to temporarily exceed disk quotas. This is not a problem as long as it is not chronic.

Do not, under any circumstances, remove user files arbitrarily and without proper warning.

A typical scenario is when all the users on the system know they should try to limit disk use in their home accounts to about 20 MB (about 40,000 512-byte blocks). User norton consistently uses more than twice this limit. These are the steps you take to alleviate the problem:

1. Try to meet with the user and find out why he or she is using this much disk space. There may be legitimate reasons that require you to reconsider the disk use policy and perhaps increase the amount of available disk space.

2. If the user is merely saving an inordinate number of outdated files, suggest that he or she back up the files onto tape and remove them from the system. For example, many users save electronic mail messages in enormous mailboxes for long after the messages are useful. Saving the files to tape keeps them handy, while saving disk space.

3. If you cannot meet with the person, or cannot discuss the matter with them, try sending them electronic mail.

   If you use a script that automatically checks disk use (with diskusg) and sends mail to users who exceed their quotas, note that people get used to these messages after some time and start to ignore them. Send the particular user a personal message, stating that you need to discuss the situation with him or her.

4. Sometimes a user is not aware that data is available elsewhere on the system, or on other accessible workstations at the site. A user may have personal copies of site-specific tools and data files. Work with the user to reduce this kind of redundancy.

5. Make sure the user is still active on the system. Sometimes people leave an organization, and the site administrators are not immediately informed.

   Also, the user may not need the account on a particular workstation any longer and may not have cleaned up the files in that account. To see if this is the case, check the last time the user logged in to the system with the finger(1) command:

   finger norton

   Among other information, finger displays the date and time the user last logged in to the system. This information is read from /etc/wtmp, if it exists.

6. If in an extreme case you must remove a user's files, back them up to tape before removing them. Do not take this step lightly. Removing user files unnecessarily can disrupt work and engender ill-will from your coworkers. Make sure you give the user plenty of advance notice that you are going to copy the files to tape and remove them from the system.

   As an added precaution, you may wish to make two copies of the tape and send one copy to the user whose files you remove. Make sure you verify that the tapes are readable before you remove the files from the system.