Disk Quotas Feature in Windows

Before you start

Objectives: Learn what are Disk Quotas and why are they used in Windows environment. Links to specific examples are located at the end of the article.

Prerequisites: no prerequisites.

Key terms: disk, quotas, space, limit, specific, users, volume, article, command, examples

What are Disk Quotas

Disk Quotas feature enables us to limit each users use of the space on our volume. That way we can conserve disk space. By using Disk Quotas we can track and restrict disk consumption. To enable quotas we have to have an NTFS formated volume. Quotas can be enabled on local volumes, network volumes and removable storage. We can also only track space usage. This is called Soft quotas. On the other hand, tracking and restricting disk usage is called Hard quotas. When working with quotas, we have an option to enforce the disk quotas. By failing to set up enforcement, the users will be allowed to exceed the limits that we have set up previously. So, to really limit disk usage, we need to set up enforcement. Disk Quotas can be set to ‘Disabled’, ‘Tracked’, or to ‘Enforced’. We also have the ability of setting up warning limits. This will let our users know that they are approaching their limits.

To manage disk quotas from the command line, we can use the fsutil quota command. Disk Quotas are usually used on servers, but they can also be used on client workstations. We set the quotas on the volume, not on the individual folders or files. Each NTFS volume or partition on the disk has its own set of Disk Quotas, even if they are on the same disk. We can create exceptions to the limits based on users. This means that we have to manually add specific users to the exception list.

The quotas are based on the file ownership. As user starts creating new files, that counts towards their disk quotas. When we enable quotas, we have to set the limits on space usage on particular volume. This only applies to new users. If the user already has files on that partition, the Disk Quota doesn’t apply to that user. To limit disk usage for existing users, we have to edit their quota entries. When we go to quota entries, we will see that there’s already a default generic quota entry for all new users. Here we can add additional users or groups of users, and then apply specific quotas to those users. This applies to all users except the ‘Administrators’ group. The quota is never applied to the administrators. System and application files count toward Disk Quotas, so the user account which installs software needs a higher limit.

If a user exceeds the quota limit, we can delete files owned by the user, change ownership of files (quota limits are enforced based on owned files), move files to other volumes (quota limits are enforced on a volume or partition basis), or increase the quota limit. We cannot reduce the amount of space used by files by compressing them. Quotas count the uncompressed size of a file toward the quota limit. If we need to remove the quotas, we will have to take the ownership away from those particular users, and then reset their limits. We cannot delete a users account quota until we remove or take ownership of all users files on the volume.


We have separate demo articles about quota management in Windows: