Disk quotas are used to specify the amount of disk space a user is allowed on specific NTFS volumes. You can specify disk quotas for all users, or you can limit disk space on a per-user basis.
Before you administer disk quotas, keep in mind the following aspects of disk quota management:
Disk quotas can be specified only for NTFS volumes.
Disk quotas apply only at the volume level, even if the NTFS partitions reside on the same physical hard drive.
Disk usage is calculated on file and folder ownership. When a user creates, copies, or takes ownership of a file, that user is the owner of the file.
When a user installs an application, the free space that will be seen by the application is based on the disk quota availability, not on the actual amount of free space on the volume.
The user also only sees the space available as defined by the quota limitation.
The calculation of disk quota space used is based on actual file size. There is no mechanism to support or recognize file compression.
Disk quotas are not applied to or enforced for the Administrator account or for members of the Administrators group.
The following sections describe how to set up and monitor disk quotas.
Configuring Disk Quotas
You configure disk quotas through the NTFS volume Properties dialog box or through from Windows Explorer by right-clicking the drive letter in the Explorer listing and select Prop-erties. In the volume’s Properties dialog box, click the Quota tab to see the dialog box shown in Figure 2.1. When you open the Quota tab, you will see that disk quotas are dis-abled by default.
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F I G U R E 2 . 1 The Quota tab of the volume Properties dialog box
Table 2.1 describes the options that can be configured through the Quota tab.
Notice the traffic light icon in the upper-left corner of the Quota tab. It indicates the status of disk quotas, as follows:
A red light means that disk quotas are disabled.
A yellow light means that Windows XP is rebuilding disk quota information.
A green light means that the disk quota system is enabled and active.
T A B L E 2 . 1 Disk Quota Configuration Options
Option Description
Enable quota management. Specifies whether quota management is enabled for the volume.
Deny disk space to users exceeding the quota limit.
Specifies that users who exceed their disk quota will not be able to override their disk allocation. Those users will receive “out of disk space” error messages.
Select the default quota limit for new users on this volume.
Allows you to define quota limits for new users. Options include not limiting disk space, limiting disk space, and specify-ing warnspecify-ing levels.
Select the quota logging options for this volume.
Specifies whether logged events that relate to quotas will be recorded. You can enable the logging of events for users exceeding quota limits or users exceeding warning limits.
Monitor, Manage, and Troubleshoot Access to Files and Folders 41
The next sections explain how to set quotas for all new users as default quotas, and how to set quotas for a specific user.
Setting Default Quotas
When you set default quota limits for new users on a volume, those quotas apply only to users who have not yet created files on that volume. Users who already own files or folders on the vol-ume will be exempt from the quota policy. Users who have not yet created a file on the volvol-ume will be bound by the quota policy.
To set the default quota limit for new users, access the Quota tab of the volume Properties dia-log box and check the Enable Quota Management box. Click the Limit Disk Space To radio but-ton, and enter a number in the first box next to the option. In the drop-down list in the second box, specify whether disk space is limited by KB (kilobytes), MB (megabytes), GB (gigabytes), TB (ter-abytes), PB (pet(ter-abytes), or EB (exabytes). If you choose to limit disk space, you can also set a warn-ing level, so that users will be warned if they come close to reachwarn-ing their limit.
If you want to apply disk quotas for all users, apply the quota when the volume is first created. That way, no users will have already created files on the vol-ume, and thus, they will not be exempt from the quota limit.
Setting an Individual Quota
You can also set quotas for individual users. There are several reasons for setting quotas this way:
You can set restrictions on other users and at the same time allow a user who routinely updates your applications to have unlimited disk space.
You can set warnings at lower levels for a user who routinely exceeds disk space.
You can apply the quota to users who already had files on the volume before the quota was implemented and thus have been granted unlimited disk space.
To set an individual quota, click the Quota Entries button in the bottom-right corner of the Quota tab. This brings up the dialog box shown in Figure 2.2. To modify a user’s quota, double-click that user. This brings up a dialog box similar to the one shown in Figure 2.3. Here, you can specify whether the user’s disk space should be limited, and you can set the limit and the warning level. If the user does not appear in the Quota Entries dialog box, you can add them by selecting Quota New Quota Entry and specifying the user through the Select Users dialog box.
F I G U R E 2 . 2 The Quota Entries for Volume dialog box 4362.book Page 41 Wednesday, August 18, 2004 1:56 PM
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F I G U R E 2 . 3 The quota settings for a user
Monitoring Disk Quotas
If you implement disk quotas, you will want to monitor the quotas on a regular basis. This allows you to check disk usage by all users who own files on the volume with those quotas applied.
Disk quota monitoring is accomplished through the Quota Entries dialog box (see Figure 2.2), which appears when you click the Quota Entries button in the Quota tab of the volume Properties dialog box. The dialog box shows the following information:
The status of the user’s disk quota, represented as follows:
A green arrow in a dialog bubble means the status is OK.
An exclamation point in a yellow triangle means the warning threshold has been exceeded.
An exclamation point in a red circle means the user threshold has been exceeded.
The name and logon name of the user who has stored files on the volume
The amount of disk space consumed by the user on the volume
The user’s quota limit
The user’s warning level
The percentage of disk space consumed by the user in relation to their disk quota