Once you have created the virtual tape libraries using either the default or custom virtual tape library types, you can use them to back up data. Because virtual libraries were designed with the look and feel of physical tape libraries, the backup application can use virtual libraries in much the same way as physical libraries.

For example, if the backup application requests information from a virtual tape that is currently in the virtual library, the media changer (virtual mechanical arm) of the virtual library retrieves the virtual tape from its slot and puts it in a virtual tape drive. The backup application can then access the data on the virtual tape. This task is nearly identical to that of a physical tape library.

In fact, a virtual tape library provides a backup application with the same functionality as a physical tape library, except of course that a virtual library is much faster and more reliable.

Each virtual library has an entry/exit port (EEP), virtual tape slots, virtual tape drives, and a robotic arm. Most of these components, with the exception of the robotic arm are displayed in the NearStore VTL GUI.

EEP

The one NearStore VTL component that is not shared by physical tape libraries is the entry/exit port (EEP), (although it is somewhat analogous to a physical library entry/exit port). This is the component that exports virtual tapes to physical tape and imports physical tape to virtual tapes. You can initiate imports and exports manually or via the backup application.

Virtual volume slots

Just as physical tape libraries have slots for cartridges, virtual libraries have slots for virtual tapes. The number of slots are defined by type of which the virtual library is based.

Virtual volume cart

Each NearStore VTL also has a virtual tape cart. This cart houses virtual tapes that have been created for, but not moved into, the virtual library. If the option to automatically move virtual tapes from the entry port to a slot is turned off, each newly created virtual tape is stored in the cart. This does not include volumes that are the result of a physical tape import.

Virtual tapes in the cart cannot be seen by the backup application.

When you create virtual tapes for a virtual library that is full, NearStore VTL stores these virtual tapes in the overflow cart. This means that it is possible to create more virtual tapes than can fit into the virtual library.

You cannot move virtual tapes directly from the cart to the virtual library. Any virtual tapes that are in the cart remain there until the mail slot (import/export) is available. Then the NearStore VTL moves the next virtual tape from the cart to the mail slot.

See the section called “Working with Virtual Libraries” for more information on enabling and disabling the Automatically Move Volume from Entry Port to Slot feature.

Virtual tape drives

Each virtual library has one or more virtual tape drives. Like physical tape drives, virtual tape drives have a native capacity. In addition, virtual tape drives can support tape optimization. See the section called “Working with Virtual Libraries” for more information.

Virtual Tapes

Virtual tapes are the NearStore VTL equivalent of physical tapes. When you perform a backup, the data is sent to a virtual tape. The backup application identifies each virtual tape by its label. This label is a virtual barcode for the virtual tape. Because you can export virtual tapes to physical tapes, the NearStore VTL can match the labels of virtual tapes with the barcodes of physical tapes. This means the backup application can track the data that it exports whether it is contained in a virtual tape or a physical tape.

See the section called “Using Virtual Tapes” for more information.

Moving the cursor over a virtual tape enlarges the view of the volume and displays the virtual tape’s label.

Virtual volume vault

The vault in the upper left-hand corner of the NearStore VTL interface is a tool that you can use to manually export virtual tapes.

In order to export a virtual tape, you use the drag-and-drop technique to move the virtual tape to the vault.

Manually manipulating a virtual library

Aside from the automated manipulation initiated by the backup application, you can manually manipulate virtual tape libraries and volumes. This is equivalent to opening the front door of a physical tape library. For example, you can manually take the virtual tape out of the import/export slot and move it to a virtual tape drive during the import of a physical tape, This enables the backup application to access the data on the physical tape without having to import all of the data.

For example:

You select a specific virtual library using the drop-down pick list at the top of the page.