CISE Help & Resources
Home Disk Space
The main source of disk space for each user is in their home directory. Home directories are on disks provided by the department for general use. These disks are shared among all people with accounts on the CISE computer network (including all students, staff, and faculty).
Home disks are shared by dozens, or even hundreds of users. When a home disk fills up, no user on that disk can work. As a result, it is very important to keep strict control on the amount of disk space allocated to each user. This is done using disk quotas.
A disk quota is the amount of disk space that is allocated to each user. The user can use this amount freely, without any restriction or timelimit. A user is never allowed to exceed their quota.
It is very important that the user stay below their quota. If the user is very close to the quota, many operations may fail since the user will not be allowed to create new files. This is especially true of reading email.
- Home Disk Quotas
- Monitoring Disk Quota
- Quota Extensions
- Efficient Use of Disk Space
- Quota FAQ
Home Disk Quotas
The current allowed quota are:
| Type of Account | Quota |
|---|---|
| Guest | 25 |
| Undergrad | 75 |
| Grad | 90 |
| PhD | 150 |
| Faculty | 1200 |
| Staff | 330 |
Monitoring Disk Quota Usage
To monitor your disk space usage, type the command:
cd; quota -v
A good way to see how close the disk is to being filled is the df command:
cd; df -k .
To check your quota:
% quota -v
To check your mail quota:
% mailquota -v
To determine which directories have the highest usage:
% cd % du -k | sort -n
To determine which files in a given directory have the largest size:
% cd some/dir % ls -l | sort +4n
There are man pages on the quota, du, and df commands.
Quota Extensions
In the past, home disk quota extensions have been allowed with little or no regulation. As a result, many grad students and faculty ended up with quotas that were much higher than the departmental policy. As a result, some home disks became overbooked (which leads to disks filling up and stopping everyone on the disk from working), and available disk space was almost completely used up (leaving no space for new accounts). Recently, this has been almost entirely eliminated, and we are trying to avoid quota extensions in as many cases as possible.
Ideally, we want to use the disks efficiently, so we allocate almost all of the space on the home disks to users. This means that giving any of the users an extended quota is tricky. To do so usually means either overbooking the disk. Alternately, the home directory can be moved to another disk, but this leaves a hole on the old disk (which we'd like to avoid in the interest of efficient usage of the departmental disks) and causes extra work and the chance for error.
In order to receive an extended quota, a user must demonstrate several things:
- That the need is genuine. The task truly cannot be performed with the current quota.
- None of the other sources of disk space describe below are available, or fit the needs of the task. Note: in virtually every instance, Project Space is used to fill an individual's need to additional disk space.
In every case, a quota extension will be temporary, so the user must plan on getting back below quota at the end of the period allowed.
Efficient Use of Disk Space - Browser Cache
One of the biggest single uses of disk space is the browser disk cache. If you are running near you quota, you may want to reduce or disable you disk cache.
To do this in Netscape 6, select the Edit Menu, then select Preferences. In the preferences window, select click on Advanced, followed by Cache. In the Cache window, reduce the Disk Cache size and click on Clear Disk Cache.
Because we are running a proxy which caches for the entire system, it is safe to disable the disk cache entirely (by setting it to a size of zero) and using it instead. For instructions on this, click here.
Efficient Use of Disk Space - Unnecessary Files
There are many types of files which can (usually) be removed safely. These include:
- Core file (
core) - Emacs files (
#filename#, filename~) - Object files (
*.o) - Other files that can be automatically regenerated if needed (
*.aux, *.dvi, etc.)
Efficient Use of Disk Space - Infrequently Used Files
Files that are not used frequently can be compressed using the gzip or bzip2 commands.
Efficient Use of Disk Space - Miscellaneous Hints
Here are some sample commands to help you determine where the disk space is being used, and how to clean up.
To find all core files:
% cd % find . -name core
or to find all object files:
% cd % find . -name \*.o
Relevant man pages are: find, du, quota.
Quota FAQ
- I just became a grad student. How do I get a higher quota?
- Go to the CISE 114 lab and log in as register. It will ask you if you want to register for an account or renew an existing one. Choose the renew option, and when it asks for your status, choose graduate student or PhD student as appropriate. Follow all remaining instructions and your new quota should take effect within a couple days.
- My quota is higher than the policy. What should I do?
- As stated above, in the past, quota extensions have been allowed much too freely. We are slowly trying to bring them back down to where they are supposed to be. Remember, the disk space you are using is provided freely by the department and is shared by over 1000 active users. Please do your part by staying under the official quota.