Removable media are important aspects of Microsoft Windows Server 2003 networks, especially when it comes to backups. In Windows Server 2003, you can create backups on fixed drives or removable drives. Managing backups on fixed drives is fairly straightforward. Backups are written to backup files and restored from backup files on a hard disk. By using removable drives, you have tapes or discs to manage as well as media pools and media libraries. If you use a tape drive, for example, tapes are your media. The tapes and the tape drive form a library in which backups are written to one or more tapes. Sets of tapes are managed through media pools, which reflect the usage and state of the media.
To help administrators better manage media, media pools, and media libraries, Windows Server 2003 uses the Removable Storage snap-in and the Removable Storage service. You use the snap-in to manage removable media and, in turn, the snap-in relies on the related service to handle necessary tasks. You can use the Removable Storage Management snap-in to perform many media management tasks, including the following:
Mounting and dismounting media
Creating media pools and managing media pool properties
Inserting and ejecting media in an automated tape library
Configuring operators that can manage removable storage
Managing operators requests and the request queue
Removable Storage is only available on servers running Microsoft Windows 2000 or later, and only authorized users can manage Removable Storage. To manage Removable Storage, you must be an administrator, a member of Backup Operators, or an authorized user.
The sections that follow examine essential media management concepts and administrative tasks.
Storage media and the storage device used to read and write to the media form a media library in much the same way as books and shelves form a traditional library. Windows Server 2003 supports both automated media libraries and nonautomated libraries:
Automated media libraries hold multiple media sets and can have multiple drives for reading and writing media. These libraries support automated library management and can have robotic subsystems for loading and unloading media. Other features can include bar-code readers, built-in support for cleaner cartridges, doors for inserting and ejecting tapes, and more. Another name for an automated media library is a robotic library.
Nonautomated libraries are single-drive devices without robotic subsystems. You manually insert media sets and there is no automated system for switching between multiple media sets. Another name for a nonautomated library is a stand-alone drive.
The library unit and the media used in the library form a Removable Storage system. As in a real library, Removable Storage keeps tracks of all media used in the system whether they are in the library unit or offline on a shelf. You can use this feature to create media inventories and to track down files for recovery. Whenever you bring a new library unit online, Removable Storage attempts to configure the library automatically.
Note
With Small Computer System Interface (SCSI)–based robotic libraries, the automated configuration might fail. If this happens, it is usually because the library unit uses multiple drives and those drives aren't on the same SCSI bus as the media changer. The drives and the media changer must be on the same SCSI bus. In addition, robotic libraries must support drive-element address reporting. Otherwise, automatic configuration fails.
A media pool is a collection of tapes or discs that are managed together. With Removable Storage all media belongs to a pool of a specific media type. The concept of a media pool is very dynamic. Libraries can have multiple media pools, and some media pools can span multiple libraries.
Media pools can also be used to establish a hierarchy in which top-level media pools contain lower-level media pools, and these media pools in turn contain collections of tapes or discs. For example, you could create top-level media pools called IS_Data, Marketing_Data, and HR_Data. The IS_Data pool could in turn have media pools called Exchange, SQL_Server, and ServerApps. A media pool that contains other media pools cannot contain individual tapes or discs.
Removable Storage categorizes media pools into types. The different types of media pools are these:
Unrecognized Unrecognized media pools contain media that Removable Storage does not recognize as well as new media that hasn't been written to yet. To make Unrecognized media available for use, move the media to the Free media pool. If you eject the media prior to doing this, the media are automatically deleted from the Removable Storage database and no longer are tracked.
Free Free media pools contain media that are not currently in use and do not contain useful data. These media are available for use by applications.
Import Import media pools contain media that Removable Storage recognizes but that have not been used before in a particular Removable Storage system. For example, if you are transferring media from one office to another, the media might be listed as Import. To reuse the media at the new location, move the media to a Free media or application media pool.
Application Application media pools contain media that are allocated to and controlled by an application, such as Windows Server 2003 Backup. Administrators and Backup Operators can control application media pools as well. Application media pools can be configured to draw media automatically from Free media pools as necessary. Once allocated, application media cannot be moved between media pools.
Free, Unrecognized, and Import media pools are referred to as system media pools. Unlike application media pools that you can delete, you cannot delete system media pools.
You access the various types of media through Computer Management. Start Computer Management. Expand Storage, Removable Storage, and then Media Pools. As Figure 23-1 shows, you'll see nodes labeled Free, Import, and Unrecognized. These media types are managed by Remote Storage.
Figure 23-1. Removable Storage is used to manage media pools, libraries, and individual tapes or discs.
Free, Import, and Unrecognized are configured as top-level media pools that contain other media pools. In most cases, they contain the media pools Removable Media and CD-ROM. If your system has robotic library units or other types of removable drives, you might see additional media pools. These media pools can be configured to store other media pools or media of a specific type. For details, see the section entitled "Changing Library Media Types" later in this chapter.
Note
Media pools for removable drives that don't contain media might not be displayed. If this happens, insert media into the drive and the necessary pool is added automatically.
Following the system media types, you'll find media pools for application media. In most cases, the default application media pools are Backup and Remote Storage. You use the Backup media pool with Windows Server 2003 Backup and the Remote Storage media pool with Windows Server 2003 Remote Storage. You can create additional media pools for use by applications or configure applications to create their own media pools.
Other nodes of Removable Storage are used as follows:
Libraries Shows the libraries available for use and provides menu options for managing their drives and media. Also provides tracking for offline media.
Work Queue Shows the status of operations and allows you to manage entries in the work queue to resolve conflicts and cancel requests.
Operator Requests Shows service requests that have been submitted by Removable Storage or by another application. These requests are messages asking a specific operator to perform a necessary task, such as inserting media, servicing a library unit, or cleaning a drive.
The media state tells you the operational status of media. You can view media state through the related library or the related media pool.
To access media through the related library, start Computer Management, expand Storage, Removable Storage, and then select Libraries. Select the library you want to work with.
To access media through the related media pool, start Computer Management, expand Storage, Removable Storage, and then select Media Pools. Select the media pool you want to work with.
All media has two states: a physical state that reflects movement, and a side state that reflects usage (of a particular side of the media). The physical and side states that you can see are summarized in Table 23-1.
Table 23-1. Physical and Side States for Media
State Type | State | Description |
|---|---|---|
Physical | Idle | Media is currently not in use or is shelved offline. |
In-Use | Media is being used. | |
Loaded | Media is mounted and data is available for read/ write operations. | |
Mounted | Media is mounted but data is not available for read/write operations. | |
Unloaded | Media has been dismounted and is ready to be removed. | |
Side | Allocated | Media has been allocated for use by a specific application. |
Available | Media is available for use by an application. | |
Completed | Media is available for use but cannot be used for write operations. The media is full. | |
Decommissioned | Media has reached its allocation maximum and is no longer available for use. | |
Imported | Media's label type is recognized, but its label ID is not. | |
Incompatible | The media type is not compatible with the library and should be removed. | |
Reserved | Media is two-sided. One side has already been allocated to an application, and the other is reserved for use by the application. | |
Unprepared | Media is in a Free media pool but does not have a Free media label. | |
Unrecognized | Media's label type and label ID are not recognized. |
As you see in Table 23-1, the media label type and ID play an important role in determining the state of the media. The label type identifies the format used to record information on the media, such as the Microsoft Tape Format (MTF). The label ID is a unique identifier that is based on the library and location of the media.
If Removable Storage recognizes the label type but not the label ID, it usually means that you've moved the media from one location to another and this is why the media has the Imported state and is placed in the Import media pool.
If Removable Storage doesn't recognize the label type or label ID, you're trying to use a tape of unknown origin. The tape might have come from a different operating system or an unsupported application.
Note
With read-only or write-once optical media, such as CD-ROM or DVD-ROM, Removable Storage doesn't use media identifiers. Instead, Removable Storage uses the volume and serial number on the disc.
Together, the label type and label ID are referred to as media identifiers. Media identifiers are recorded on the media the first time you insert it into a library and are thereafter used to track the media. If the library supports bar codes, you can use bar codes to identify media as well. The advantage of using bar codes is that you don't have to mount the media to read its identifier and then dismount it. This makes searching and inventory tracking quick and efficient.
Media must be formatted properly for it to be recognized by Removable Storage. Compact discs must be formatted with the CD-ROM File System (CDFS). Other types of removable media must be formatted with the File Allocation Table (FAT), FAT32, or NTFS file system (NTFS).
Like other objects in Windows Server 2003, Removable Storage has specific access permissions. You can set access permissions for all of Removable Storage as well as for individual media pools, libraries, and media. Table 23-2 summarizes the available user permissions from lowest to highest. Higher-level permissions inherit the capabilities of lower-level permissions.
Table 23-2. Access Permissions for Removable Storage
Permission | Meaning for Removable Storage | Meaning for Media, Media Pools, or Libraries |
|---|---|---|
Use | Grants Read access to Removable Storage but not necessarily to media, media pools, or libraries. | Grants Read access to the individual media, media pool, or library. Allows user to insert and eject media and take inventory in a library. |
Modify | Grants Read/Write access. User can create media pools, manage the work and requests queues. | Grants Read/Write access. User can change properties of the media, media pool, or library. |
Control | Grants complete control to user. User can change permissions, delete media pools, and delete libraries. | Grants complete control. User can change permissions, delete media pools, and delete libraries. |
Note
Keep in mind these permissions apply to the Removable Storage system and not the files that might be stored on media. NTFS access permissions still apply to files on NTFS-formatted media.
Initially, Removable Storage is configured for management by the operating system and administrators. Backup Operators can use and control Remote Storage. Normal users are granted only limited access, which might be necessary when working with both Removable Storage and Remote Storage. If you use Removable Storage for purposes other than backup and recovery operations, you might want to grant access to other users and groups. However, only administrators and Backup Operators have the necessary permissions to back up and restore files on computers. Thus, even if you grant an operator control, that user might not be able to back up and restore files.