Volume Management

The topics in this section provide instructions for several common volume management tasks. You can use the Backup administration program (nwadmin), the nsradmin interface, or the nsrjb program to perform volume management tasks.

For specific instructions on how to use the windows in the Backup administration program, refer to the online help. For details on the nsradmin and nsrjb commands, refer to the nsradmin(1m) and nsrjb(1m) man pages. The nsrjb command is also described in Appendix B, Command Line Reference Utilities.

How to Mount a Volume in an Autochanger

To mount a volume in an autochanger, select the autochanger device in the Devices attribute and then mount the device, or enter the following command at the shell prompt:

# nsrjb -l slot

Place an adhesive label on the outside of the autochanger to identify its device pathnames. When you use more than one autochanger, this practice is especially useful to remind you which device pathnames belong to the autochanger.

How to Label a Volume in an Autochanger

Select a backup device in an autochanger from the Devices attribute, select a label template in the Pools resource, and make sure there are volumes in the autochanger. Then start the volume label operation.

To label volumes in an autochanger from the command line, enter the following command at the shell prompt:

# nsrjb -L 

Because it takes Backup some time to label the volumes in the autochanger, you might want to perform the volume label process when you do not need to back up or recover files.

Backup starts to label the media in the autochanger with the label displayed in the Starting With attribute. The First Slot and Last Slot attributes determine the range of slots containing volumes that Backup labels.

If you label a specific range of volumes, the name in the Starting With attribute must match the label template. If you label a single volume, you can use any name; it does not have to match the label template. To label a single volume, put the same value in the First Slot and Last Slot attributes.

When a valid Backup label already exists on the media that you are trying to label, Backup displays a confirmation message to keep you from accidentally relabeling the media. When a volume is relabeled, you cannot recover its contents under the previous label. When you select OK to confirm, the volumes in the slots are loaded, labeled, and unloaded.

Unmount all volumes in the autochanger to prevent you from accidentally relabeling existing volumes when you reload the autochanger with new volumes.

For more information on labeling volumes see "Storage Management Operations (Labeling and Mounting) ".

How Backup Uses Barcode Labels with Autochangers

The use of external barcode labels to label media provides two distinct advantages: it significantly speeds up volume inventory and provides improved accuracy for internal volume labels.

With barcode labels, the inventory operation is fast and efficient because you do not have to load the volumes into the device. Instead, the autochanger scans the external barcode labels with an infrared light while the volumes remain in their slots. Performing an inventory with barcode labels greatly reduces the time it takes to locate a volume or determine the contents of a volume.

Barcode labels also provide greater accuracy because the labels are attached to the media prior to being loaded and scanned in the autochanger. After the autochanger scans the barcode label, Backup records and tracks the label in the media database.

Backup only uses barcode labels to inventory volumes. Backup uses the internal volume label (usually created with a label template) to identify the volumes required for backup and recovery. However, Backup displays both the barcode label and the volume label in the pending messages, and the Volumes resource contains both the volume label and its associated barcode label.

You do not have to label existing volumes with barcode labels if they are stored in a vault or offsite for long periods at a time. This is because you do not inventory these volumes often, if ever. However, if you have volumes you use often for recovery or for overwriting with new data, it is beneficial to label them with barcode labels. When your volumes are labeled with barcodes, you save hours of time when you inventory your volumes.

If you decide to use barcode labels on your existing volumes, you must first apply the barcode labels to the existing volumes. Then, load and mount each volume individually so Backup can match the barcode label to the existing volume label.

You can purchase a variety of barcode labels from a third-party vendor. You can choose numeric, alphanumeric, or a special combination of numbers and characters to meet your labeling needs. You can even order barcode labels that match your current volume labeling scheme.

If you label your volumes with the server name and an extension such as 001, order a range of labels starting with server_name.001 and ending with server_name.100. Labeling instructions for barcode labels are usually provided with your autochanger hardware documentation. If you have questions about barcode labels, contact the hardware manufacturer.

Using a consistent labeling scheme helps you better organize and track your volumes. It also aids the inventory process if all the volumes, rather than a limited number of them, use barcode labels.

When Backup relabels volumes automatically, it reuses the original volume label name. You can only change the label name if you relabel the volumes manually. Backup scans the barcode label during the labeling process and updates the media database with the new volume name and its associated barcode label.

If the autochanger inventory becomes outdated, either by rebooting your system or by opening the autochanger door, you can update the information about the autochanger's contents by performing an inventory. The administration program provides a graphical Inventory command; you can also issue the nsrjb -E -I command, as root, at the shell prompt. A reset operation also updates the information about the contents of the autochanger. Regardless of which method you use to update the contents, every slot in the autochanger is initialized.

How to Label an Autochanger Volume With Barcodes

A volume must have a volume label, but it does not require a barcode label. Use the Jukeboxes resource to associate barcode labels with your volumes.

To label Backup volumes with barcode labels, follow these steps:

1. Apply the barcode labels to your volumes.

2. Place the volumes with the barcode labels in the autochanger.

3. Display the Jukeboxes resource.

4. Set the Barcode Reader and Match Barcode Labels fields to Yes.

5. Label the volumes using either the Backup administration program or nsrjb -L.

   ---

   Caution -

   Do not use identical barcode labels for any of your Backup volumes. Using identical labels defeats the purpose of using barcode labels. If you try to label a second volume with an identical barcode label and you enabled Match Barcode Labels in the Jukeboxes resource, Backup displays an error message and does not allow you to label the second volume. To correct the problem, apply a different label and begin the labeling process again.

   ---

   If you choose not to match the volume label to the barcode label, you should create and attach volume labels to the outside of your media.

   If you choose not to have the labels match, it is suggested that you label the volumes in this manner:

1. Attach all the barcode labels to the media, then load the volumes in the autochanger.

2. In the Jukeboxes resource, set the Barcode Reader attribute to Yes, and set the Match Barcode Labels attribute to No.

   If you set both Barcode Reader and Match Barcode Labels to Yes and you forget to attach a barcode label, you receive an error message that says there is no barcode label for that volume.

3. Begin the labeling process.

   Backup uses the next available label from the label template for the volume name. Backup labels the volumes and records both labels in the media database.

4. After Backup completes the labeling process, display the Volumes resource to determine the volume label and barcode label for each volume.

5. Create your own volume labels to attach to the volumes.

   Use the information in the Volumes resource to match the correct volume labels to the barcode labels. This is the easiest way to make sure that you attach the correct volume labels to the volumes with barcode labels.

How the Inventory Process Works

When Backup labels the contents of an autochanger, it registers the location of the volumes in the autochanger slots when it assigns the volume label. As long as you do not change the volumes in the autochanger after labeling them, Backup can access the volumes because each volume label is assigned to a specific slot.

However, if you change the contents of the autochanger without performing the labeling process, or if you move volumes into new slots, you must inform Backup that the autochanger now holds a different set of labeled volumes or that the volumes are in a different order. This is called taking inventory.

When you inventory the volumes in the autochanger, Backup reads the label of each volume and records its slot number. For example, if you have more than one job pack for an autochanger, you must take inventory each time you remove one job pack and load another one into the autochanger, if you do not label the volumes in the new job pack.

Backup provides the capability of reading barcode labels to speed up the inventory process. We strongly recommend that you use barcode labels if you have a large number of volumes or change your autochanger contents often. See "How Backup Uses Barcode Labels with Autochangers" for more information.

How to Inventory Volumes in an Autochanger

To inventory volumes in an autochanger when you have moved or added volumes you can either start the inventory operation in the Backup administration program or at the command line:

# nsrjb -Iv

After completing an inventory, Backup registers the contents of the autochanger and then proceeds with its network-wide backup and recover services.

Determining Which Volumes Are Used for Backup

The Available Slots attribute enables you to control which volumes Backup uses for backing up data. Backup uses all of the volumes in the autochanger for recoveries. However, you can control which volumes Backup automatically selects for backups by designating a range of available slots in the autochanger.

For example, you might designate slots 1 through 5 for your Backup backups in an autochanger that contains 10 slots. The entries can be a range of slot numbers or a single slot number.

With two-sided media, the number of available slots is always half the number of labels (or sides of the optical disks). For example, if you have 32 optical disks, labeled atlas.001.a to atlas.032.b, you have 64 labels (and 64 sides). However, the number of available slots is 32.

Make sure you place volumes in all the available slots of the autochanger so Backup can proceed uninterrupted with an automatic backup.

Checking Autochanger Notifications

Backup uses e-mail to send notices about Backup events. The software uses the three Tape Mount Request notifications to inform you that the autochanger needs attention. The Tape Mount Request 1 notification is undefined so you can create your own notification message.

The following situations require attention:

• The volumes in the autochanger are 90% full.

• The autochanger needs more volumes to continue.

• The autochanger has a mechanical problem.

• The autochanger device needs cleaning.

• The cleaning cartridge in the autochanger needs replacing.

The Notifications resource contains tape mount and device cleaning request notifications pertaining to autochanger operations.

See "Preconfigured Notifications " for more information.

If the volume is loaded in the autochanger, Backup can automatically mount the correct volume so that the recovery proceeds. If Backup requires volumes for a recovery that are not loaded in the autochanger, you receive a notice in the Pending window of the Backup administration program.

After you correct an autochanger problem, you may need to mount a volume before continuing to back up or recover files. Check the Pending window in the Backup administration program for messages.

Suggestions for Operating Autochangers

This section provides additional suggestions to help you use your autochanger and backup media effectively and reliably.

Recycling Versus Adding More Backup Volumes

Backup can save files on volumes marked appen (appendable) in the Volumes resource. If the volumes inside the autochanger are marked full, they cannot receive additional backups.

You can do one of the following with volumes marked full:

• If you need to keep the volumes for long-term storage, remove the full volumes and replace them with new media.

• If you do not need the data on the full volumes, you can manually change the mode to recyc in the Volumes resource. Backup overwrites the data with new backups, but maintains the existing labels. This is the only instance where you do not need to relabel a volume to make it eligible to be overwritten with new data.

The mode of a volume is automatically changed to recyclable when all the save sets on the volume have passed the time period specified by its retention policy.

There are advantages to both recycling media and adding more media to a pool. By recycling, you reuse the same volumes and do not add new volumes to the pool. However, the media may wear out over time and have a higher failure rate.

On the other hand, if your site requires that you maintain the backups in storage for a certain period of time, then you may have to add more media to the volume pool instead of recycling it. For example, an autochanger may need new volumes every three months if your company policy is to maintain the backups for a year. In this case, you have to keep adding new media to the pool until you can recycle the volumes that contain expired or old backups.

Using Pools with an Autochanger

If you plan to have full and nonfull backups, we recommend that you estimate the number of volumes needed for your full backups and assign them to the Full pool. This ensures that your full backups are in a consecutive range of slots in the autochanger, which makes it easy for you to remove all the volumes at the same time.

Calibrating the Devices

Check the autochanger manufacturer's documentation for information about the frequency and method for calibrating the loading mechanism for the autochanger device.

How to Move Media Inside an Autochanger

Always use Backup to move the media inside an autochanger. If you physically move the media, the autochanger inventory becomes outdated. If this occurs inadvertently, follow these steps:

1. Reset the autochanger:

   # nsrjb -H

2. Inventory the autochanger contents:

   # nsrjb -I -E

   Refer to Appendix B, Command Line Reference Utilities and the nsrjb man page for details on the nsrjb program.