Chapter 2. Configuring a NearStore VTL Appliance

The configuration tasks provide step-by-step configuration instructions that you can use to configure the features that are available with the NearStore VTL appliance.

Configuration sections include:

Working with Virtual Libraries

NearStore VTL virtual libraries are the logical equivalents of physical tape libraries: they have one or more tape drives, cartridge slots, mailbox ports (also called entry/exit ports, CAP ports or I/O ports), a barcode reader, and a medium changer. Virtual libraries appear to the backup application in exactly the same way as physical tape libraries. This means that the backup application can work with virtual libraries without any configuration changes. Simply add the virtual library to the backup application as you would a physical library and back up your data.

Because you will, at some point, want to export your virtual tapes to physical tape, you need to create virtual libraries with drives that are compatible with the drives of your physical library. This means that both the capacity and type of the virtual and physical drives should be the same. The NearStore VTL comes with a number of predefined virtual tape drive types that are compatible with most virtual libraries. If you want to restore directly from physical tape, the virtual and physical drives must be of the same type.

If you decide to create a virtual library that is fully populated with virtual tapes, you need to ensure that the labels (virtual barcodes) of your virtual tapes match the barcodes of the corresponding physical tapes. The best way to understand this is to visualize a one-to-one correlation between virtual tapes and the corresponding physical tapes. For each virtual tape, there is a physical tape with the same capacity and barcode.

You can also have the NearStore VTL create the virtual tapes based on the physical tapes that are currently in your physical tape library. See the section called “Working with Virtual Tapes” for more information.

There are multiple advanced configuration options that affect the way in which you can use virtual libraries. The first is the customer option. When you enable this option, you can create customer accounts and assign virtual libraries to them. When a virtual library is assigned to a specific customer, only that customer (and the NearStore VTL administrator) can access it.

To use the customer option, you must enable it before you create the virtual libraries that you want to associate with the customer account. See Working with Customer for more information.

The next option to consider is the library access (Host access control) feature. This feature gives you the ability to associate specific hosts with specific virtual libraries. These associations can be either dedicated or shared. When an association is shared, multiple hosts can access the same virtual library. When an association is dedicated, only a specific host can access the virtual library. You can enable library access either before or after you create a virtual library.

See the section called “Managing Host Access” for more information.

Virtual library tasks include:

Viewing Virtual Libraries

The Virtual Library List screen, displays a list of all virtual libraries currently configured for the NearStore VTL. The configuration parameters (such as the name and capacity) for each virtual library are listed.

From the Configuration Tasks menu, located on the left side of the screen, click the Virtual Libraries task category.

The Virtual Library List screen appears and the NearStore VTL displays the following:

Library Name—gives the name of the virtual library.

Customer Name—(optional) gives the name of the customer with which the virtual library is associated. This field is displayed only if the Use Customer option has been enabled from Configuration Tasks >Advanced.

Capacity Allocated—specifies the amount of disk space allocated to the virtual tapes in the virtual library.

Capacity Used—gives the amount of disk space currently used by the virtual tapes in the specified virtual library.

Library Type—specifies the type of library being used by the virtual library. Virtual library types are displayed on the Virtual Library Type List screen, available from Configuration Tasks >Advanced >Virtual Library Types.

#Virtual Tapes—provides the number of virtual tapes that are in the virtual library. If there are no virtual tapes in the virtual library, the capacity allocated will be 0 Gigabytes.

#Slots—gives the number of cartridge slots in the virtual library.

#Drives—provides the number of virtual tape drives in the virtual library.

Tape Optimization—tells you whether tape optimization is enabled. If it is not enabled, the NearStore VTL displays Disabled.

Storage Pool—(optional) gives the name of the storage pool with which the virtual library is associated. This field is displayed only if the Use Storage Pools option has been enabled from Configuration Tasks >Advanced.

Creating Virtual Libraries

Each NearStore VTL virtual library is associated with a virtual library type. This virtual library type defines the characteristics of the virtual library, such as the type of virtual tape drives that the library uses and how many cartridge (virtual tape) slots it has. The NearStore VTL comes with a number of virtual library types that you can use. Alternatively, you can create a custom virtual library type if your needs are not addressed by one of the default types.

It is important to keep in mind that there is a one-to-one correlation between virtual tapes and physical tapes. This means that you should pick a virtual tape drive type that matches the physical tape drive or drives to which you will be exporting virtual tapes.

Note

When you move a virtual tape, it retains the attributes of its source virtual library.

Complete this task to create virtual tape libraries:

From the Configuration Tasks menu, located on the left side of the screen, click the Virtual Libraries task category.
Click the Create Virtual Library tab, located in the upper portion of the screen.

The Create Virtual Library screen appears.
Complete the following:

Library Nickname—provides the name of the virtual library.

Customer Name—(optional) provides a drop-down menu from which you can select a customer account. The virtual library will be assigned to the customer specified. This drop-down menu is available only if you have enabled the option to use customer accounts from Configuration Tasks >Advanced.

See Working with Customers for more information.

Library Type—selects the type of virtual library that you want to create. The library type defines the characteristics, such as the type of virtual tape drives and the number of cartridge slots, of the virtual library. You can either use a default virtual library type or create a custom one. See Working with Virtual Libraries and Creating/Editing Virtual Library Types , respectively.

Automatically Move Volume from Entry Port to Slot—select this for the virtual library to automatically move virtual tapes from the entry port to an available slot when new virtual tapes are created or imported. Otherwise, virtual tapes will appear in the import/export slot one at a time and you can move them into the slots either manually or using the backup application.

Enable Tape Cloning—NearStore VTL creates a physical copy of each virtual tape that has been modified as it is removed from the virtual tape drive. Unlike exporting, this process does not delete the virtual tape.

See Enabling Advanced Configuration Features for more information.

Use Label Constraints from Library Type—the virtual library uses the label constraints built into the library type (only available if the library type uses label constraints). Label constraints specify which characters/digits of a label/barcode do not increment as the NearStore VTL creates additional virtual tapes.

See Creating/Editing Virtual Library Types for more information.

Fully Loaded with Virtual Tapes—specifies whether the NearStore VTL creates a new virtual tape for each slot in the virtual library. In this case, the starting label for these virtual tapes must be specified. The labels of additional volumes will be incremented automatically.

Note

If the Over Allocation feature is disabled, the NearStore VTL creates only the number of volumes that the currently available disk space allows.

Starting Volume Label—gives the starting label of the virtual tapes. For example, if the starting volume label is ABC100 and there are five virtual tapes the NearStore VTL labels them ABC100, ABC101, ABC102, ABC103, and ABC104. This example assumes that there are no label constraints. If label constraints are enabled, the NearStore VTL increments only part of the label.

See Working with Virtual Tapes for more information.

Tape Optimization—NearStore VTL samples the data that the backup application sends to see at which ratio it can be compressed when exported to physical tape. This option optimizes physical tape usage.

Disk Allocation Per Tape (GB)—lets you set the maximum amount of disk space reserved for this virtual tape.

Storage Pool—(optional) provides a drop-down menu from which you can select a storage pool. The virtual library uses disk space only from the storage pool that you select. This drop-down menu is available only if the Use Storage Pool option is enabled from Configuration Tasks >Advanced.

See Working with Storage Pools for more information.

(Optional) you can click Reset to clear all of the changes that you have made to the screen.
Click Apply.

The NearStore VTL adds the new library and displays it on the Virtual Library List screen. You can manipulate the new library from the Virtual Library screen available from Daily Tasks >Virtual Libraries.

NearStore VTL then publishes the new virtual library on the SAN. It also displays it on the SCSI Addresses screen, available from Configuration Tasks >Virtual Device Access >SCSI Addresses.

If have enabled the storage pool option, the NearStore VTL uses the specified storage pool for storing this virtual libraries data. See Working with Storage Pools for detailed information. If you have selected the option to use customer accounts, the NearStore VTL associates the virtual library with the specified customer account. See Working with Customer for more information.

Deleting Virtual Libraries

When a virtual library is no longer needed, you can delete it from the configuration of the NearStore VTL appliance. By default, the NearStore VTL exports all virtual tapes that are currently present in the virtual library when you delete it. This is to assure that the data on the virtual tapes is not accidentally deleted.

Once the NearStore VTL has exported all of these virtual tapes, you need to delete the virtual library again.

Note

If you either cannot export the virtual tapes or do not wish to retain their data you have to cancel the pending exports and manually delete all of the virtual tapes in the library. Then you can delete the virtual library.

For this reason, it is a good idea to remove all virtual tapes from a virtual library before you delete it. If you are sure that you don’t need the data on the virtual tapes, you can delete the individual virtual tapes first.

See Exporting Virtual Tapes for more information.

Complete this task to delete virtual libraries:

From the Configuration Tasks menu, located on the left side of the screen, click theVirtual Libraries task category.
Click the Delete Virtual Library tab, located in the upper portion of the screen.

The Delete Virtual Library screen appears, and the NearStore VTL displays the following information:

Action—provides an option, export tape(s)/remove library, that when selected, exports any virtual tapes that are associated with the specified virtual library. It then deletes the virtual library specified.

Library Name—gives the name of a virtual library. Ensure that the correct library is selected.

Customer Name—(optional) provides the name of the customer to which the library is assigned. This field is displayed only if the Use Customer option has been enabled from Configuration Tasks >Advanced.

Capacity Used—specifies the amount of allotted disk space currently used by the virtual tapes in the specified virtual library.

Disk Used—specifies the amount of actual disk space currently used by the virtual tapes in the specified virtual library.

#Virtual Tapes—provides the number of virtual tapes associated with the virtual library.
Click in the Action field of the virtual library that you want to delete.
When prompted, Click Apply to delete the selected virtual library.

As noted, if there are virtual tapes currently in the virtual library, the NearStore VTL tries to export them before it deletes the virtual library. If there is a problem with the export, or if you do not want to save the data on these virtual tapes, you can delete/export these volumes manually.

Once the NearStore VTL exports any virtual tapes, delete the virtual library again.


Configuration Road Map		Managing Virtual Device Access