Introduction:

Managing disk space is a critical aspect of system administration, especially in multi-user environments where resources need to be efficiently allocated and monitored. Disk quotas provide a means to restrict and monitor disk usage, ensuring that users do not consume excessive space and that filesystems do not become full unexpectedly. In this technical blog, we will explore the process of setting up user and group disk quotas for filesystems on Linux systems using tools such as quota, quotaon, and quotacheck.

Understanding Disk Quotas

Disk quotas allow system administrators to enforce limits on the amount of disk space individual users or groups can consume on a filesystem. By setting quotas, administrators can prevent users from monopolizing disk resources, ensure fair usage, and receive notifications before filesystems become full.

Implementation Steps

1. Enabling Quotas

To enable quotas per filesystem, modifications must be made to the /etc/fstab file. This file contains information about filesystems and their mount points. The usrquota and grpquota options need to be added to the relevant filesystems in order to enable user and group quotas, respectively.

sudo vim /etc/fstab
# Add usrquota and/or grpquota options to the filesystems that require quotas:
/dev/vdb1 /mybackups xfs defaults,usrquota,grpquota 0 2

After modifying /etc/fstab, remount the filesystem(s) for the changes to take effect:

sudo systemctl reboot

2. Creating Quota Database Files

Once quotas are enabled, quota database files need to be created to store quota information. This is achieved using the quotacheck command. For ext4 filesystems, additional steps are required to enforce quotas:

sudo quotacheck --create-files --user --group /dev/vdb2

3. Turning On Quota Limits

After creating the quota database files, turn on quota limits using the quotaon command:

sudo quotaon /mnt/

4. Assigning Quota Policies

Quota policies specify the limits for individual users or groups. This can be done using tools such as edquota to edit the quota configuration for a specific user or group:

sudo edquota --user aaron

Monitoring and Management

Once quotas are set up, it's essential to monitor usage and adjust quotas as needed. Tools like quota allow administrators to view current usage and enforce limits:

sudo quota --user aaron

Conclusion

In conclusion, setting up user and group disk quotas for filesystems is a crucial aspect of system administration for managing disk space efficiently and ensuring fair resource allocation. By following the steps outlined in this blog and leveraging tools such as quota, quotaon, and quotacheck, administrators can effectively implement and enforce disk quotas to prevent disk space misuse and maintain system stability. Proper management of disk quotas is essential for maintaining system integrity and optimizing resource utilization in multi-user environments.