Administrator's Guide

Example of a Manual Library: Setting Up Two 8mm Tape Drives

In the following example, two 8mm drives are attached to the server system. The example takes you through the steps necessary to get ADSM to use the devices for storing client data.

Because an operator must mount tapes for these drives, you must define them as part of a manual library to ADSM. You can use this example as a guide when configuring other manual tape and optical devices. This example presents the procedure with a minimum of customization. If you want to do more, see the references in the steps for more details.

Attach the Device to the Server System

Install the SCSI adapter card in your system, if not already installed.
Determine the SCSI IDs available on the SCSI adapter card to which you are attaching the device. Find one unused SCSI ID for each drive.
Follow the manufacturer's instructions to set the SCSI ID for the device to the unused SCSI ID that you found. Usually this means setting switches on the back of the device.
Attention: Each device connected in a chain to a single SCSI bus must be set to a unique SCSI ID. If each device does not have a unique SCSI ID, you may have serious system problems.
Follow the manufacturer's instructions to attach the device to your server system hardware.
Attention:
1. Power off your system before attaching a device to prevent damage to the hardware.
2. You must attach a terminator to the last device in the chain of devices connected on one SCSI adapter card. Detailed instructions should be in the documentation that came with your hardware.
Install the appropriate device driver. See "Installing Device Drivers".
Determine the name for the device, which is needed to define the device to ADSM.
For a tape drive, the device name is a special file name with the form /dev/rmt/mtx, where x is the number assigned when the drive was set up with its device driver.

Define the Device to ADSM

Define a manual library for ADSM by entering the following command on the command line of an ADSM administrative client. The name of the library is MANUAL8MM. The library type is manual because an operator must mount the tapes.
```
define library manual8mm libtype=manual
```
Define the drives that belong to this manual library.
```
define drive manual8mm drive01 device=/dev/rmt/mt1
```
```
define drive manual8mm drive02 device=/dev/rmt/mt2
```
Both drives belong to the MANUAL8MM library. In this example, the drive known to the device driver by the special file name /dev/rmt/1mt is given the ADSM name DRIVE01. The device /dev/rmt/2mt is given the ADSM name DRIVE02. You might prefer to have the device driver name and the ADSM name match.
See "Defining Drives" and Appendix B. "Supported Devices and Device Configuration Worksheets".
Classify drives according to type and format by defining ADSM device classes. For example, if you want to use the 8500 recording format for the two drives in the MANUAL8MM library, use the following command to define a device class named TAPE8MM_CLASS:
```
define devclass tape8mm_class devtype=8mm
format=8500 library=manual8mm 
```
See "Defining and Updating Device Classes for Tape Devices".
To check what you have defined, enter the following commands:
```
query library
```
```
query drive
```
```
query devclass
```
See "Requesting Information about Libraries", "Requesting Information about Drives", and "Requesting Information about a Device Class".
Create the storage pool to use the devices in the device class you just defined. For example, define a storage pool named TAPE8MM_POOL associated with the device class TAPE8MM_CLASS:
```
define stgpool tape8mm_pool tape8mm_class maxscratch=20
```
Key choices:
1. Scratch volumes are labeled, empty volumes that are available for use. If you allow scratch volumes for the storage pool by specifying a value for the maximum number of scratch volumes, ADSM can use any scratch volumes available, without further action on your part. If you do not allow scratch volumes (MAXSCRATCH=0), you must perform the extra step of explicitly defining each volume to be used in the storage pool.
2. Collocation is turned off by default. Collocation is a process by which the server attempts to keep all files belonging to a client node or client file space on a minimal number of volumes. Once clients begin storing data in a storage pool with collocation off, you cannot easily change the data in the storage pool so that it is collocated. To understand the advantages and disadvantages of collocation, see "Collocation on Sequential Access Storage Pools" and "How Collocation Affects Reclamation".
See "Defining a Primary Storage Pool".

Update the ADSM Policy

You can do one of the following:

Have clients back up data directly to tape.
Have clients back up data to disk storage. Then let ADSM migrate the data to tape when the amount of disk storage used reaches the migration threshold.

The following steps assume that you are modifying the standard, IBM-supplied policy objects, named STANDARD, to allow clients to back up data directly to tape. However, if you want some clients to back up directly to tape and some to disk, keep the standard policy as is. For the clients that need to back up directly to tape, define new policy (policy domain, management class, copy groups) and assign these clients to the new policy domain. For details on the standard policy, see "Using the Standard Policy". For how to define new policy, see "Creating Your Own Policies".

Clients Back Up Directly to Tape

You can choose to have clients back up directly to the new tape storage pool that you defined.
Key choice: If you back up directly to tape, the number of clients that can back up data at the same time is equal to the number of drives available to the storage pool (through the mount limit of the device class). If you have only one drive, only one client at a time can back up data.
Performance of tape drives is often lower when backing up directly to tape than when backing up to disk and then migrating to tape. Backing up data directly to tape usually means more starting and stopping of the tape drive. Backing up to disk then migrating to tape usually means the tape drive moves more continuously, meaning better performance.

Update the backup copy group so that the destination for backups is the new tape storage pool, TAPE8MM_POOL. For example:

update copygroup standard standard standard
type=backup destination=tape8mm_pool

Note:

You may want clients in the STANDARD policy domain to be able to choose whether to back up directly to disk or to tape. If so, instead of updating the copy group in the STANDARD management class, you can define a new management class and a new copy group in the STANDARD domain. See "Defining and Updating a Backup Copy Group".

Activate this modified policy:
```
activate policyset standard standard
```
See "Activating Policy Sets".

Clients Back Up to Disk and Then Data Migrates

You can have clients back up data to disk storage. Then let ADSM migrate the data to the new tape storage pool when the amount of disk storage used reaches the migration threshold. For example, you can have data migrate from the default disk storage pool, BACKUPPOOL, to the new storage pool, TAPE8MM_POOL, by using the following command:

update stgpool backuppool nextstgpool=tape8mm_pool

If you have not changed the defaults for BACKUPPOOL, ADSM will migrate data from this disk pool to the TAPE8MM_POOL when the disk pool is 90% full. See "Defining or Updating Storage Pools".

Register Clients to the Policy Domain

If you updated the default STANDARD policy to use the new storage pool as a destination for backups from clients, the clients must be registered to that policy domain. To register a client named ASTRO to the STANDARD policy domain and assign the client the password CADET, enter this command:

register node astro cadet

You do not need to specify a policy domain because the STANDARD policy domain is the default.

You can change the domain to which a client is assigned by using the UPDATE NODE command.

For information on options when registering clients, see "Administrator Registration of Client Nodes".

Label Volumes

Ensure that volumes are available to ADSM in the library.

You must label volumes that do not already have a standard label. Use the LABEL LIBVOLUME command from the server console or an administrative client. For example, to use one of the 8mm drives, enter this command to label a volume with the id of vol001:
```
label libvolume manual8mm vol001
```
Keep enough labeled volumes on hand so that you do not run out during an operation such as client backup.
What you need to do next depends on whether you are using scratch volumes or private volumes:
- If you are using only scratch volumes, you have nothing more to do except ensure that there are enough scratch volumes available. For example, you may need to label more volumes. As volumes are used, you may also need to increase the number of scratch volumes allowed in the storage pool that you defined for this library.
- If you want to use private volumes in addition to or instead of scratch volumes in the library, you must define volumes to the storage pool you defined. The volumes you define must have been already labeled. For information on defining volumes, see "Defining Storage Pool Volumes".

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