Businesses often back up data to a variety of storage devices ranging from high-performance disk devices to slower and less expensive tape devices. Administrators must balance the data availability requirements of users with the costs of storage devices.
This section discusses how to evaluate your current environment to determine the device classes and storage pools for your server storage.
Before configuring devices, evaluate the hardware available to the server:
The server expects to have exclusive use of the drives. If another application tries to use a drive used by the server, some server functions may fail.
Note: | For sequential access devices, categorize the type of tape cartridge based on capacity. For example, standard cartridge tapes and enhanced capacity cartridge tapes require different device classes. |
Also consider the storage resources available on the target server. Ensure that the target server has enough storage space and mount points to handle the load from the source server.
As an example of mapping devices to device classes, assume you have the following devices to use for server storage:
You can map storage devices to device classes as shown in Table 2.
Table 2. Mapping Storage Devices to Device Class
Device Class | Description |
---|---|
DISK | Storage volumes that reside on the internal disk drive
TSM provides one DISK device class that is already defined, and you cannot define another device class for disk storage. |
CARTRIDGE_E | Enhanced Capacity Cartridge System Tape (ECCST) volumes used with 3490E tape devices |
CARTRIDGE_B | Standard Cartridge System Tape (CST) volumes used with 3480 or 3490 Base tape devices |
You must define any device classes that you need for your tape devices. See Chapter 6, Managing Device Classes for information on defining tape device classes to support your physical storage environment.
After you have categorized your storage devices, identify availability, space, and performance requirements for client data that is stored in server storage. These requirements help you determine where to store data for different groups of clients and different types of data. You can then create storage pools that are storage destinations for backed-up, archived, or space-managed files to match requirements.
For example, you determine that users in the business department have three requirements:
These files should be stored on disk. However, you need to ensure that data is moved from the disk to prevent it from becoming full. You can set up a storage hierarchy so that files can migrate automatically from disk to the automated tape library.
To match user requirements to storage devices, the administrator defines
storage pools and device classes. See Table 3.
Table 3. Mapping Storage Pools to Device Classes, Libraries, and Drives
Storage Pool | Device Class | Volume Type | Storage Destination | ||
---|---|---|---|---|---|
BACKUPPOOL | DISK | Storage volumes on the internal disk drive | For a backup copy group for files requiring immediate access | ||
SPACEMGPOOL | DISK | Storage volumes on the internal disk drive | For a management class for space-managed files that require immediate access | ||
ARCHTAPEF | CARTRIDGE_E | ECCST volumes | For an archive copy group for files requiring quick, reliable access | ||
BACKTAPE | CARTRIDGE_E | ECCST volumes | For backup copy groups for files not requiring immediate access | ||
ARCHTAPES | CARTRIDGE_B | CST volumes | For archived data not requiring immediate access | ||
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Before a device can be used by TSM, the device must be configured to the operating system as well as to TSM. For information on configuring devices, see the following sections: