Administering Disk Quotas

Disk quotas monitor volume use to prevent users from affecting others' use of the volume. For example, if a user saves 50 MB on a volume on which each user has been allocated 50 MB of space, some of this data must be moved or deleted before additional data is written to the volume. Other users can continue to save up to 50 MB of space on that volume.

Note

Disk Quotas do not prevent adminstrators from allocating more space than is available on the disk. For example, on a 1 GB volume that is used by 100 users, each user might be allocated 100 MB of space to allow each user a reasonable amount of disk space.

Disk quotas are based on file ownership and are independent of the location of the files on the volume. If a user moves files from one folder to another on the same volume, volume space usage does not change; if the user copies the files to a different folder on the same volume, the volume space usage doubles.

The administrator can set default quotas for the volume or quotas for specific users on a volume. A new user receives the default quota unless the administrator established a quota specifically for that user. The administrator can view the level of quota tracking, the default quota limits, and the per-owner quota information. The per-user quota information contains the user's hard quota limit, warning threshold, and quota usage.

If you do not want to use the default disk space limit and warning threshold values for a particular user, use the New Quota Entry feature to set up quota thresholds and limits before the user actually writes data to the volume.

User quota entries cannot be deleted if a user still owns files on the volume; all files owned by that user must either be deleted or moved to another volume, or ownership of the files must be transferred to another user.

Enabling Disk Quotas

When you enable quotas on a volume that already contains files, the disk space used by all users who have copied, saved, or taken ownership of files on the volume up to that point is calculated. The quota limit and warning level are then applied to all current users and to all new users. You can then disable or set different quotas for specific users. You can also set quotas for specific users who have not yet copied, saved, or taken ownership of files on the volume.

For example, you can set a quota of 5 MB for all users of \\Main\General, while ensuring that two users who work with larger files have a 10 MB limit. If both users already have files stored on \\Main\General, select both users and set their quota limit to 10 MB. However, if one or both users do not have files stored on the server when you enable quotas, use the Select Users property sheet to set their quota limit to a value higher than the default for new users.

Local and Remote Implementations

Disk quotas can be enabled on volumes residing on both local computers and remote computers. On local computers, quotas can be used to limit the amount of space available to users who log on to the local computer. On remote computers, quotas can limit volume usage by remote users.

You can use quotas to ensure the following:

• Multiple users can share resources on the same computer.
• Disk space on public servers is not monopolized by one or more users.
• Users do not use excessive disk space on a shared folder on your computer.

To enable quotas on remote volumes, they must be formatted as the version of NTFS included with Windows 2000 and be shared from the root directory of the volume. Also, you must be a member of the Administrators group on the remote computer to enable and manage quotas.

System files are included in the volume usage of the person who installed Windows 2000 on the local computer. When implementing disk quotas on a local volume, make sure to take into account the disk space used by these files. Depending on the free space available on the volume, you might want to set a high quota limit or no limit for the user who installed the operating system.

Auditing Disk Space Use

Enabling quotas causes a slight increase in server overhead and a slight decrease in file server performance. By periodically enabling and then disabling quotas, you can take advantage of the auditing capabilities provided by Windows 2000 disk quotas without reducing the performance of your file server.

To create a record of the audit, save a copy of the data to another application, such as Microsoft® Excel.

Exceeding Disk Quota Limits

When you select the Deny disk space to users exceeding quota limit option, users who exceed their limit receive an "insufficient disk space" error and cannot write additional data to the volume without deleting or moving files. Individual programs determine their own error handling for this condition. To the program, it appears that the volume is full.

By leaving this option cleared, you can allow users to exceed their limit. This is useful when you do not want to deny users access to a volume, but want to track disk space use on a per-user basis. You can also specify whether or not to log an event when users exceed either their quota warning level or their quota limit.

When you select the Log event when a user exceeds their quota limit option, an event is written to the system log when a user exceeds the limit. Administrators can view these events with Event Viewer, filtering for Disk event types. Unless you set a trigger to do so, users are not warned of this event.

Event Viewer builds a historical, chronological record of which users exceeded their quota warning level and quota limits, and when they exceeded them. However, it does not provide information about which users are currently over their quota warning level.

For more information about enabling disk quotas, see Windows 2000 Server Help.

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