JLab Disk Quotas

What is a Disk Quota?

Disk Quotas are a means of limiting the amount of actual disk space used by a user or a group. On multi-user systems, such as the CUE systems at JLab, common disk space is shared among all users from some central system. Without disk quotas one user or group would have the capability to utilize all physical disk space that is shared by everyone who has access to it.

How are quotas implemented?

There are two different types of quota systems in use at JLab, personal quotas and group quotas. These quotas determine how much data can be stored on the central file servers by an individual user or by a group.

Personal quotas are assigned to every user. This quota limits how much data can be owned by a particular user in the /home filesystem. This is typically all the files in your /home/<username> directory and all of its subdirectories. This includes your “J” drive on your PC that actually resides on the central fileservers if you are part of the Common User Environment (CUE). Files that may be in other user’s home directories, but are owned by you still count towards your quota. Initial quotas on new accounts are set at 1GB. For accounts that require more than 1GB, you must contact the IT Division Help Desk and submit a ccpr which justifies the need for more quota.

Group quotas are assigned to groups upon request to the IT Division Help Desk. Group areas are intended to be a place where several users can share files easily.Access to group areas is via membership in the appropriate group. The group areas are found in “/group” on Unix and on the “M” drive on your CUE PC. Initial group quotas are 1Gb per group. Files in the /group file system are counted towards the quota by group ownership, not location. This means that files in /group/aes only count towards the aes quota IF they are owned by group aes. This has caused some confusion in the past when users that are members of multiple groups create files in one group area with group ownership of a different group.

Your Disk Quota Responsibilities

As a user in JLAB CUE it is your responsibility to clean up any unnecessary or extraneous data and files that may be found in your centrally provided directories. This would include any non-work related files, or any files that you know are of no use and will not be needed again. If you keep your home directory clean of any unnecessary files and information you will rarely experience disk quota problems. Additionally disk space is a very expensive resource and if unimportant data and files is removed there is a definite savings.

How can I check my quota?

All users can check the quota of users or groups using the Quota Check utility.

Disk Quota Email

If you exceed or have reached 95% of your allotted disk quota you will receive the following email:

		WARNING!!!

You have exceeded 95% of your quota on the central fileservers.
Should you exhaust your disk quota you will no longer be able to receive
Electronic Mail, and you may not be able to log in to fix the problem.
It is strongly suggested that you take steps to reduce your disk usage
as soon as possible.

If you are able to log into your account you should go in and try to 
clean up your home directory and subdirectories. Try to remove as many 
large files that you no longer need, remove any temporary files that may 
not be needed anymore, clean up your email folders removing any messages 
that you do not need anymore, in general remove any files that you no 
longer need to keep around. 

See the Computer Center Disk Quota page at:

http://cc.jlab.org/quotas

for more information on the disk quotas implementation at JLAB.

If you are unable to login, or you are unable to clean up your home 
directory sufficiently contact the contact the Computer Center Help Desk 
if you need assistance.

The Help Desk is reachable at x7155 (8:00 - 4:30 Mon-Fri), 
or on the web at:
    http://cc.jlab.org/helpdesk

Thank you, 
JLab Computer Center. 

What should I do if I get this message?

If you are able to log into your account you should go in and try to clean up your home directory and subdirectories. Try to remove as many large files that you no longer need, remove any temporary files that may not be needed anymore, in general remove any files that you no longer need to keep around. If you are unable to login, or you are unable to clean up your home directory sufficiently contact the helpdesk as directed in the email for assistance.