Steps to allocate a maximum amount of disk space a user or group may use.

Configuration of disk usage quotas on Linux - Perform the following as root:

1. Edit file /etc/fstab to add qualifier "usrquota" or "grpquota" to the partition. The following file system mounting options can be specified in /etc/fstab


* To enable user quota support on a file system, add "usrquota" to the fourth field containing the word "defaults".

...
/dev/hda2 /home ext3 defaults,usrquota 1 1
...


* Replace "usrquota" with "grpquota", should you need group quota support on a file system.

...
/dev/hda2 /home ext3 defaults,grpquota 1 1
...


* Need both user quota and group quota support on a file system?

...
/dev/hda2 /home ext3 defaults,usrquota,grpquota 1 1
...


This enables user and group quotas support on the /home file system.

2. touch /partition/aquota.user
where the partition might be /home or some partition defined in /etc/fstab.
then
chmod 600 /partition/aquota.user

The file should be owned by root. Quotas may also be set for groups by using the file aquota.group




3. Re-boot or re-mount file partition with quotas.

* Re-boot: shutdown -r now
* Re-mount partition: mount -o remount /partition


After re-booting or re-mounting the file system, the partition will show up in the list of mounted filesystems as having quotas. Check /etc/mtab:

...
/dev/hda5 / ext3 rw,usrquota 0 0
...

4. quotacheck -vgum /partition
or
quotacheck -vguma

The options used are as follows:

* a — Check all quota-enabled, locally-mounted file systems
* v — Display verbose status information as the quota check proceeds
* u — Check user disk quota information
* g — Check group disk quota information



5. quotaon -av
System Response: /dev/hda6: user quotas turned on

quotaon - enable disk quotas on a file system.
quotaoff - turn off disk quotas for a file system.



6. edquota -u user_id
Edit directly using vi editor commands. (See below for more info.)
For example: edquota -u user1

* System Response (RH 7+):

Disk quotas for user user1 (uid 501):
Filesystem blocks soft hard inodes soft hard
/dev/hda5 1944 0 0 120 0 0


o blocks: 1k blocks
o inodes: Number of entries in directory file
o soft: Max number of blocks/inodes user may have on partition before warning is issued and grace persiod countdown begins.
If set to "0" (zero) then no limit is enforced.
o hard: Max number of blocks/inodes user may have on partition.
If set to "0" (zero) then no limit is enforced.

If editing group quotas: edquota -g group_name

To verify that the group quota has been set, use the command:

quota -g group_name


Also please note that quota is assigned in KB



7. List quotas:
quota -u user_id

For example: quota -u user1
System response:

Disk quotas for user user1 (uid 501):
Filesystem blocks quota limit grace files quota limit grace
/dev/hda6 992 50000 55000 71 10000 11000


If this does not respond similar to the above, then restart the computer: shutdown -r now



Quota Reports:

* Report on all users over quota limits: quota -q
* Quota summary report: repquota -a

*** Report for user quotas on device /dev/hda5
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
root -- 4335200 0 0 181502 0 0
bin -- 15644 0 0 101 0 0
...
user1 -- 1944 0 0 120 0 0


No limits shown with this user as limits are set to 0.



Cron:

Quotacheck should scan the file system via cronjob periodically (say, every week?). Add a script to the /etc/cron.weekly/ directory.
File: /etc/cron.weekly/runQuotacheck

* Linux Kernel 2.4: Red Hat 7.1 - Fedora Core 3:

#!/bin/bash
/sbin/quotacheck -vguma

* Linux Kernel 2.2: Red Hat 6/7.0:

#!/bin/bash
/sbin/quotacheck -v -a

(Remember to chmod +x /etc/cron.weekly/runQuotacheck)

Note: You can refer more details from the urls:

http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/custom-guide/ch-disk-quotas.html
http://www.yolinux.com/TUTORIALS/LinuxTutorialQuotas.html