LPI Linux Certification/Managing Disk Quota
Candidates should be able to manage disk quotas for users.
- Key knowledge area(s):
- Set up a disk quota for a filesystem.
- Edit, check and generate user quota reports.
- The following is a partial list of the used files, terms and utilities:
On a system, root can manage the usage of disk space per user and per filesystems. The two limits that can be setup are: The soft limit (soft =) specifies the maximum amount of disk usage a quota user is allowed to have. The hard limit (hard =) specifies the absolute limit on the disk usage a quota user can't go beyond it. There is also the possibility to setup a grace period that will enforce the soft limit only after an amount of time specified.
Setting up quotas for users
1) The keyword usrquota or/and grpquota must be added in file /etc/fstab for the partition interested.
/dev/fd0 /home/yann/mnt auto rw,noauto,user,usrquota 0 0 /dev/hda5 /home ext2 defaults,usrquota,grpquota 1 2
2) Add in each root filesystems the file user.quota or/and group.quota.
touch /mnt/aquota.user touch /home/aquota.user touch /home/aquota.group chmod 600 /mnt/aquota.user chmod 600 /home/aquota.user chmod 600 /home/aquota.group
Only root can do the quota administration and once the empty files have been created some disk quota can be set such as:
- Soft limitation on number of files and inodes.
- Hard limitation on number of files and inodes if the grace time is set.
Setting up quotas for users
3) Check the setting
quotacheck -v mnt quotacheck: Scanning /dev/fd0 [/home/yann/mnt] done quotacheck: Checked 6 directories and 1 files
4) Enable quota on the disk
quotaon -av /dev/fd0 [/home/yann/mnt]: user quotas turned on
5) Customize the disk quota limits:
$ edquota -u yann Disk quotas for user yann (uid 500): Filesystem blocks soft hard inodes soft hard /dev/fd0 15 0 0 4 0 0
$ edquota -g yann
$ edquota -t Grace period before enforcing soft limits for users: Time units may be: days, hours, minutes, or seconds Filesystem Block grace period Inode grace period /dev/fd0 7days 7days
To list quotas for an user or group, use quota.
quota [options] [user|group]
- -u:Default, print user quotas.
- -g:Print group quotas for the group of which the user is a member.
- -q: Print a more terse message, containing only information on filesystems where usage is over quota.
quota -u yann
Display a quota report
To display a quota report, use repquota.
repquota [options] [user|group]
- -a: Report on all filesystems indicated in /etc/mtab to be read-write with quotas.
- -g: Report for group.
$ repquota /dev/fd0 *** Report for user quotas on device /dev/fd0 Block grace time: 7days; Inode grace time: 7days Block limits File limits User used soft hard grace used soft hard grace ---------------------------------------------------------------------- root -- 8 0 0 2 0 0 yann -- 15 0 0 4 0 0
- Setup a soft limitation for any users that have their home directory in /home to 500M.
- Change the grace time to 0.
- Log as the user and check if the limitation works.