Linux Disk Quotas
Add the quota options to the vfstab:
LABEL=/home /home ext3 defaults,usrquota,grpquota 1 2
Remount the filesystem (rebooting will work).
Initialize the quotas:
Edit quotas:
# edquota user
# edquota -g group
Report disk usage:
Periodically you should check things to make sure they are OK (ie from cron):
As always,
man is your friend.