Virtual Tape Libraries

Overview

A Virtual Tape Library (VTL) is a disk-based library that emulates the traditional tape devices and formats, and can be installed onto any disk space. Refer to the manufacturer's documentation to see if a disk-based storage subsystem supports VTL emulation mode.

Follow the manufacturer's instructions to create the virtual tape library and make sure that the MediaAgent can detect the virtual arm changer and the drives created.

Contact your software provider for the latest list of virtual tape libraries supported.

For more information about about hardware compatibility, see Compatibility Matrices.

The NearStore virtual tape libraries and Fujitsu ETERNUS CS High End require special configuration.

• See Configure a NearStore Virtual Tape Library for more information.

• See Configuring Fujitsu ETERNUS CS High End Virtual Tape Library for more information.

Configure a Virtual Tape Library

Use the following steps to configure a virtual tape library:

1. Follow the manufacturer's instructions to create the virtual tape library and make sure that the MediaAgent can detect the virtual arm changer and the drives that are created.

2. Use the appropriate library type to configure the virtual tape library.

   • Direct-attached library (See Direct-Attached Libraries for more information)

   • Direct-attached shared library (See Direct-Attached Shared Libraries for more information)

   • SAN-attached library (See SAN-Attached Libraries - Configure for more information)

3. When the library is configured, right-click the library in the Expert Storage Configuration dialog box, and then click Properties.

   The Library Properties dialog box appears.

4. Click the Is a Virtual Library Tape check box, and then select Generic from the list.

   This configures the system to ignore all of the media and drive usage/cleaning thresholds, which do not apply to virtual tape libraries.

5. Click OK.

   Once the virtual tape library is configured, it supports most of the operations that are supported by actual tape libraries, depending on the manufacturer's implementation.

Configure a NearStore Virtual Tape Library

Configure the NearStore VTL

The NearStore virtual tape libraries require special configuration.

1. Follow the manufacturer's instructions to create the virtual tape library and make sure that the MediaAgent can detect the virtual arm changer and the drives that are created.

   Also make sure that you enable the shadow tape feature while creating the virtual tape, using the manufacturer's instructions.

2. Use the appropriate library type to configure the virtual tape library.

   • Direct-attached library (See Direct-Attached Libraries for more information)

   • Direct-attached shared library (See Direct-Attached Shared Libraries for more information)

   • SAN-attached library (See SAN-Attached Libraries - Configure for more information)

3. To enable the shadow tape feature after the library is configured, right-click the library in the Expert Storage Configuration dialog box, and then click Properties.

   The Library Properties dialog box appears.

4. Click the Barcode Reader Installed check box.

5. Click the Is a Virtual Library Tape check box, and then select NetApp NearStore from the list.

   This configures the system to ignore all of the media and drive usage/cleaning thresholds that do not apply to virtual tape libraries.

6. Click OK.

   The shadow tape feature is now enabled in the virtual tape library.

   Once the virtual tape library is configured, it supports most of the operations that are supported by actual tape libraries, depending on the manufacturer's implementation.

Export Data from a NearStore VTL

When the virtual tape is exported to a physical tape, the physical media that contains the matching barcode is loaded onto the physical library (if not already present), and the contents are copied from the virtual tape to the physical tape. When this copy operation is complete, the virtual tape is marked as a shadow tape and this shadow tape is available for restore operations until the data expires.

Restore Data from a NearStore VTL

When the data from an exported virtual tape is restored, one of the following occurs:

• Shadow tape is available

  In this case, the shadow tape is available in full, and the data is restored from the shadow tape.

• Shadow tape is not available, and the matching physical media is present in the library

  In this case, the shadow tape is recreated from the physical media that contains the matching barcode. The data is then restored from the recreated shadow tape.

• Shadow tape is not available, and the matching physical media is not present in the library

  In this case, the system prompts you to import the physical media that contains the data. Once the media is imported into the physical library, the shadow tape is recreated from the physical media that contains the matching barcode. The data is then restored from the recreated shadow tape.

  Note

  • Once the restore operation is complete, we recommend that you export the virtual tape back again. This ensures that the virtual tape becomes a shadow tape again, and the disk space is reclaimed, if required.

  • In addition, we recommend that you schedule Vault Tracker policies to check and export full virtual tapes periodically.

    Note

Configure a Fujitsu ETERNUS CS High End Virtual Tape Library

Procedure

1. On the ribbon in the CommCell Console, click the Storage tab, and then click Expert Storage Configuration.

   The Expert Storage Configuration dialog box and the Select MediaAgents dialog box appear.

2. In the Available MediaAgents list, select the MediaAgents whose devices you want to detect or display, and then click Add.

3. Click OK.

   A message appears.

4. Click OK.

5. In the Expert Storage Configuration dialog box that appears, click Start, and then click Detect/Configure Devices.

6. Click OK.

   The detection process starts.

   The Log dialog box appears.

7. Click OK when the detection process completes, and then click Close.

   The system detects the emulated library arm and drives and displays them as a standalone library in the Expert Storage Configuration window.

8. Right-click the Library, and then click Properties.

   The Library Properties dialog box appears.

9. Click the Is a Virtual Tape Library check box, and the select Fujitsu ETERNUS CS High End from the list.

10. Click OK.

11. Right-click the library, and then click Configure.

    The Configuration dialog box appears.

12. Click Library and all drives, and then click OK.

    The Discover Media Options dialog box appears.

13. Click Yes.

14. When the Fujitsu ETERNUS virtual tape library is configured, click Start, and then click Exit.

Prefetch the Media

For Virtual Tape Libraries (VTL), when the data required for a restore job is not available in the disk pool cache, the data has to be fetched from the physical tapes. Follow the steps, to prefetch the tapes for restores:

1. From the CommCell Browser, expand Storage Resources | Libraries | <tape_library> | Media By Location | Media In Library.

2. In the Media In Library pane, right-click the appropriate media.

3. Click Options, and then click Prefetch.

   The virtual tape is loaded into the cache.