Managing Disk Quotas | File Systems

Introduction

Disk quotas are used to limit the amount of disk space and the number of files a user or group can use on a filesystem. This tutorial covers how to set up and manage disk quotas in a Linux environment.

Step 1: Install Quota Packages

First, ensure that the necessary quota management packages are installed on your system. You can install them using your package manager. For example, on a Debian-based system, you can use:

sudo apt-get install quota

On a Red Hat-based system, use:

sudo yum install quota

Step 2: Enable Quotas on the Filesystem

To enable quotas, you need to modify the filesystem table file /etc/fstab. Open the file with your preferred text editor:

sudo nano /etc/fstab

Find the entry for the filesystem you want to enable quotas on, and add usrquota and grpquota options. For example:

/dev/sda1 / ext4 defaults,usrquota,grpquota 0 1

Save the changes and remount the filesystem:

sudo mount -o remount /

Step 3: Create Quota Files

Next, create the quota database files on the filesystem root:

sudo quotacheck -cum /

This command checks the filesystem and creates the necessary quota files.

Step 4: Enable Quota Enforcement

Enable quota enforcement using the following command:

sudo quotaon -v /

This command turns on quota enforcement on the specified filesystem.

Step 5: Set Quotas for Users

Now you can set disk quotas for users using the edquota command:

sudo edquota username

This will open a file where you can set soft and hard limits for blocks and inodes. For example:

Disk quotas for user username (uid 1001):
  Filesystem                   blocks       soft       hard     inodes     soft     hard
  /dev/sda1                    10000       5000       6000        500      300      400

Save and close the file. The soft limit is the quota limit that can be temporarily exceeded, while the hard limit is the absolute limit that cannot be exceeded.

Step 6: Check Quota Usage

You can check the quota usage for a user with the quota command:

quota username

The output will show the current disk usage and limits for the user:

Disk quotas for user username (uid 1001):
  Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
  /dev/sda1    2000    5000    6000            100      300     400

Step 7: Report Quota Status

The repquota command can be used to report the quota status for all users on a filesystem:

sudo repquota /

The output will list the quota usage for each user:

*** Report for user quotas on device /dev/sda1
Block grace time: 7days; Inode grace time: 7days
                        Block limits                File limits
User            used    soft    hard  grace    used  soft  hard  grace
---------------------------------------------------------------------- 
username    --  2000*   5000    6000  2days     100   300   400

Conclusion

By following these steps, you can effectively manage disk quotas on your Linux system. This ensures that users do not exceed their allocated disk space, helping to maintain the overall health and performance of the system.

Managing Disk Quotas in Linux