Administrator's Guide

Example of an Automated Library: Setting Up an 8mm Autochanger

For the following example, an Exabyte EXB-210 library containing two drives is attached to the server system. The example takes you through the steps necessary to get ADSM to use the devices in the library for storing client data.

You can use this example as a guide when configuring other automated tape devices. This example presents the procedure with a minimum of customization. If you want to do more, see the references in the steps.

Attach the Device to the Server System

  1. Install the SCSI adapter card in your system, if not already installed.

  2. 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, and one for the library or autochanger controller.
    Note:In some automated libraries, the drives and the autochanger share a single SCSI ID, but have different LUNs. For these libraries, only a single SCSI ID is required. Check the documentation for your device.

  3. Follow the manufacturer's instructions to set the SCSI ID for the drives and library controller to the unused SCSI IDs 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.

  4. 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.

  5. Install the appropriate device drivers. See "Installing Device Drivers".

  6. Find the device worksheet that applies to your device. See Appendix B. "Supported Devices and Device Configuration Worksheets".

  7. Determine the name for the device, which is needed to define the device to ADSM, and record the name on the device worksheet.

    The device name for each drive has the form /dev/mtx. The device name for the library controller has the form /dev/lbx. In both cases, x is the number assigned when the drive and library was set up with its device driver.
    Keep the Worksheets:The information you record on the worksheets can help you when you need to perform operations such as adding volumes to an autochanger. Keep them for future reference.

Define the Device to ADSM

  1. Define the library to ADSM. For example, for an Exabyte EXB-210 library, name the library AUTO8MMLIB. The library type is SCSI because the library is a SCSI-attached automated library, and is not an IBM 3494. Enter the following command on the command line of an ADSM administrative client: 
    define library auto8mmlib libtype=scsi device=/dev/rmt/lb3

    For automated libraries, the library type is either SCSI or 349X. The DEVICE parameter gives the device driver's name for the library, the special file name.

    See "Defining Libraries" and "SCSI Libraries".

  2. Decide whether all drives in that library will be used by ADSM. Define the drives that ADSM will use. For example: 
    define drive auto8mmlib drive01 device=/dev/mt4 element=82

    define drive auto8mmlib drive02 device=/dev/mt5 element=83

    Both drives belong to the AUTO8MMLIB library. The DEVICE parameter gives the device driver's name for the drive. In this example, each drive is given an ADSM name that matches its device driver name.
    Element address:The element address is a number that indicates the physical location of a drive within an automated library. ADSM needs the element address to connect the physical location of the drive to the drive's SCSI address. When you define a drive, the element address is required if there is more than one drive in an automated library. The element numbers are taken from the device worksheet filled out in step 7. See Appendix B. "Supported Devices and Device Configuration Worksheets" for determining the element numbers.

    See "Defining Drives".

  3. Classify drives according to type and recording format by defining ADSM device classes. For example, if you want to use the 8500 recording format for the two drives in the AUTO8MMLIB library, use the following command to define a device class named AUTO8MM_CLASS: 
    define devclass auto8mm_class devtype=8mm format=8500
library=auto8mmlib

    See "Defining and Updating Device Classes for Tape Devices".

  4. 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".

  5. Create the storage pool to use the devices in the device class you just defined. For example, define a storage pool named AUTO8MM_POOL associated with the device class AUTO8MM_CLASS: 
    define stgpool auto8mm_pool auto8mm_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 choose from the scratch volumes available in the library, without further action on your part. If you do not allow scratch volumes, 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:

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.

  1. Update the backup copy group so that the destination for backups is the new tape storage pool, AUTO8MM_POOL. For example: 
    update copygroup standard standard standard
type=backup destination=auto8mm_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".

  2. 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, AUTO8MM_POOL, by using the following command: 

update stgpool backuppool nextstgpool=auto8mm_pool

If you have not changed the defaults for BACKUPPOOL, ADSM will migrate data from this disk pool to the AUTO8MM_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.

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

Label and Check In a Library Volume

Ensure that enough volumes are available to ADSM in the library.

  1. 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 drives in the 8mm library and search for all usable volumes in the library, enter this command: 
    label libvolume auto8mmlib search=yes labelsource=barcode
overwrite=no checkin=scratch

    Keep enough labeled volumes on hand so that you do not run out during an operation such as client backup.

  2. What you need to do next depends on whether you are using scratch volumes or private volumes:

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