Centos 7 – Disk Quota Conf

As a Linux system admin we generally face low disk space issues. By implementing the user and group disk quota on the file system we can resolve the space issue.

Quota restricts the users to use only allowed disk and inodes on the particular file system. In this post we will discuss how to enable user & group disk quota on /home File system on CentOS 7 & RHEL 7

Esimene käsk – Yum install Quota

Loo failid /home/quota.user ja /home/quota.group (debianil on need failid aquota.user ja aquota.group)

touch 600 /home/quota.user 
touch 600 /home/quota.group
touch 600 /home/aquota.user 
touch 600 /home/aquota.group

chmod 600 /home/quota.user
chmod 600 /home/quota.group
chmod 600 /home/aquota.user 
chmod 600 /home/aquota.group

#Debian`il
chmod 600 /home/aquota.user
chmod 600 /home/aquota.group

 

Step:1 Add usrquota & grpquota option on /home in /etc/fstab file.
[root@linuxtechi ~]# vi /etc/fstab

Seal lisa usrquota ja grpquota näide. siin /dev/hda2 /home ext3 defaults,usrquota,grpquota 1 1

home-quotau

Save & exit the file.

In this example i have add user and group quota options on /home

Step:2 Remount  /home file system via  mount command
[root@linuxtechi ~]# mount -o remount /home

Now recheck the /home file system whether Quota is enable or not.

[root@linuxtechi ~]# mount | grep /home
/dev/mapper/centos-home on /home type ext4 (rw,relatime,seclabel,quota,usrquota,grpquota,data=ordered)
Step:3 Create Quota Database Files using quotacheck
[root@linuxtechi home]# quotacheck -cugv /home

kui eelmine käsk annab vea siis proovida seda quotacheck -cfmvF vfsv0 /home

Whereas :

-c : create quota file and don’t use the existing file
-v : verbose ouput
-u : user disk quota
-g : group disk quota

Above Command will create aquota.user & aquota.group files under /home

Turn on quota on /home using below command :

[root@linuxtechi ~]# quotaon /home/

#kui tekib probleeme quota on käsuga, siis lase need käsud läbi
1. quotaoff -guvp -a 
group quota on /home (/dev/hda7) is off 
user quota on /home (/dev/hda7) is off 
2. mount -o remount /home 
3. quotacheck -cguvamf -F vfsv0 
4. quotaon -a 

Step:4 Assign user & group disk quota via edquota commands

Syntax # edquota -u <User_Name>

# edquota -g <Group_Name>

[root@linuxtechi ~]# edquota -u jack

edquota

[root@linuxtechi ~]# edquota -g sys_admin

group-quota

As shown above we have two kind of Disk quota limits :

soft : It will warn the users if the soft limit of disk quota reached ( size is in KB), in above example for jack user soft limit is 5500 KB ( approx 5.5MB )

hard : It will not allow the users to create new files once the hard limit is reached. ( Size in KB ), in above example hard limit for jack user is 6000 KB ( approx 6 MB )

Note : We can also set the Quota on the basis of the inodes ( i.e numbers of files that the user can create on particular file system)

Let’s take an example , login as jack user and try to create a file of 8MB.

[root@linuxtechi ~]# su - jack

[jack@linuxtechi ~]$ dd if=/dev/zero of=bgfile bs=1M count=8
dm-2: warning, user block quota exceeded.
dm-2: write failed, user block limit reached.
dd: error writing ‘bgfile’: Disk quota exceeded
6+0 records in
5+0 records out
6144000 bytes (6.1 MB) copied, 0.00711317 s, 864 MB/s

As we see above soft & hard limit is exceeded for jack user. Now onwards user jack can’t create new files.

 

Step:5 Display Quota report for Users in human readable
[root@linuxtechi ~]# repquota -as
repquota
Step:6 Configure Grace Period for Soft Limit

Grace period is the amount of time during which soft limit can can be exceeded, once the grace period reached then soft limit will become the hard limit.

Use the edquota command to set Grace period .

[root@linuxtechi ~]# edquota -t

Soft-limit-grace-period

Please don’t hesitate to share your feedback and comments on this post ?