Data Storage and Management
Data Storage and Management |
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Windows 2000 introduces several new storage and storage-related features. These features, available to users and administrators, provide better flexibility, enhanced administrative control, and more efficient usage of resources. Some of the features are enhanced versions of previous Windows applications; others are new. Correct use of these features can help to improve security and reduce management costs associated with storage.
Removable Storage is a new core Windows 2000 service that manages removable storage media and robotic storage libraries. Removable Storage eliminates the need for independent software vendors (ISVs) to support these devices on a per-device basis. More importantly, Removable Storage enables multiple applications to share expensive removable media storage devices. This allows storage applications to concentrate on customer features rather than hardware issues.
As shown in Figure 2.1, Removable Storage provides a single set of application programming interfaces (APIs) that allows applications to catalog all removable media (except floppy disks and similar small capacity media), such as disk, tape, and optical media, which are either stored on shelves (offline) or in libraries (online). Also, by disguising the complexities of underlying robotic library systems, Removable Storage both lowers costs of developing and operating storage applications and provides consistency to customers who purchase these applications.
Figure 2.1 Removable Media with and Without Removable Storage
Removable Storage uses media pools to organize media. Media pools have several functions in the management of a media server, such as controlling access to media and grouping media by their use. Media pools allow media to be shared across applications, and they allow such sharing to be tracked.
Remote Storage is a hierarchical storage management application that migrates data from primary storage to secondary storage. Hierarchical storage management makes sure that data is stored in the most cost-effective method possible. Frequently accessed data is stored on high-performance disks, while data that is not accessed as often is migrated to less expensive media until it is needed again.
Regardless of where the data is stored, the file system namespace continues to provide users with access to the file. When the file is accessed, Remote Storage retrieves the file from its storage location and restores it to the file system. Supported secondary storage in Windows 2000 is limited to tape, such as digital audio tape (DAT) and digital linear tape (DLT).
Remote Storage helps manage the cost associated with large quantities of data that must be accessible. Figure 2.2 illustrates the architecture of Remote Storage.
Figure 2.2 Remote Storage
The Disk Management function is enhanced in Windows 2000. Disk Management introduces new disk layouts that provide better manageability and recoverability. Enhancements to Disk Management include a remote administration Microsoft Management Console (MMC) snap-in and an expanded fault tolerance feature set. Moreover, most volume configuration changes do not require restarting the computer.
Disk quotas are a new feature in NTFS that provide more granular control of disk storage. Quotas allow administrators to limit the amount of disk space that a user can consume on an NTFS volume.
Disk quotas provide system administrators with a powerful tool for managing storage growth. Administrators can set both soft and hard limits: when a user exceeds a warning level (soft limit), an event is logged; when a user exceeds the hard limit, they receive an Out of Disk error.
