Tivoli Storage Manager for Sun Solaris Quick Start


Using Tape and Optical Devices

Before you can use tape and optical devices with TSM, you must do the following:

  1. Attach the devices to your system, which includes physically attaching the devices, configuring the device drivers, and determining the device names.
  2. Define the following: a library for the drives, the drives, a device class, and a storage pool associated with the device class.
  3. Include the storage pool in your storage hierarchy.

To perform these tasks you can use the administrative client command line or web interface.

This section describes the following tasks:

If you want to use a tape management system with TSM see the Administrator's Guide for details.

The examples in this section set up the following configuration:



Attention

If TSM will use a tape library controlled by the Storage Tek Automated Cartridge System Library Software, you must set the CSI_HOSTNAME in the /opt/tivoli/tsm/devices/bin/rc.acs_ssi file. Define the environment variable ACSLS_SERVER_HOSTNAME in the /etc/environment or /etc/profile. You do not need to reset the variable at the next product update.


A Closer Look

Here are some concepts that can help you to set up your tape environment (see Administrator's Guide):
Storage pool migration

To prevent disk storage pools from becoming filled with client data, you can specify that client data be automatically migrated to the tape storage pool.

A disk's high migration threshold (default value: 90%) determines when data is migrated. The low migration threshold (default value: 70%) determines when migration stops. Thus data migration from the default backup disk storage pool begins when the pool is 90% full and continues until it is at 70% full or less.

Another default is to cache data (leave the data on the storage pool) even after the data has been migrated. Cached data stays on disk for quick access until the space is needed for new data.

Scratch volumes

A scratch volume is a volume that is available for TSM use. The volume is labeled, is either blank or contains no valid data, and is not defined to TSM. You must specify the number of scratch volumes that TSM can request for this pool (MAXSCRATCH parameter).

Collocation

Collocation means that the server tries to keep a client's files on a minimal number of tape volumes. It is turned off by default. 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 the Administrator's Guide.

Attaching Devices and Installing Device Drivers

For TSM to use a device, you must physically attach the devices to the server and install the appropriate device driver on your system. The following sections discuss how this is done for drives in a manual library and for the drives and controller in automated libraries.



Attaching Devices and Installing Drivers

IBM tape drives, tape autochangers, and tape libraries
Install the IBMtape device driver. For an IBM 3494, install the IBM Tape Library Driver for Sun Solaris, which includes the lmcp daemon. See Installing Device Drivers for IBM 3490, 3570, and 3590 Tape Drives, Installing Device Drivers for IBM 349X Libraries, and IBM SCSI Device Drivers: Installation and User's Guide.

Non-IBM tape drives and tape autochangers
Install the TSM device drivers. When you install TSM, you must choose whether to install the TSM device drivers for tape and tape autochanger devices. See Installing Device Drivers for how to install the device drivers.

Optical devices
Install the TSM device drivers.

The drivers are started when you start Sun Solaris. The devices must be powered on for Sun Solaris recognize them.

Determining Device Names for Tivoli Storage Manager

To identify and work with removable media devices, TSM needs the device's special file name. or devices other than the IBM 3494, the name is the special file name. For a 3494, the device name is the symbolic name you entered in the configuration file for the library. For devices other than the 3494, one or more device special file names are created during configuration. The following table shows the form of the names. In this table, x denotes a number (0-7).

Special File Name. Description
/dev/rmt/xmt Used for tape drives that are supported by the TSM device driver
/dev/rmt/xlb Used for SCSI-attached libraries that are supported by the TSM device driver
/dev/rmt/xop Used for optical drives that are supported by the TSM device driver
/dev/rmt/xst Used for IBM 3490, 3570, and 3590 tape drives, which are supported by the IBMtape device driver
/dev/rmt/xsmc Used for the medium changer (the robotics) of an IBM 3570 or an IBM 3590 B11 with Automatic Cartridge Facility (ACF) feature, which are supported by the IBMtape device driver

The special file is a symbolic link into the /devices tree of the file system. The symbolic link destination has the form:

+--------------------------------------------------------------------------------+
|/devices/.../mt@x,0:mt                                                          |
+--------------------------------------------------------------------------------+

where x is the SCSI ID of the device. The following table contains examples of special file names.

Note:This naming convention will be slightly different for Sun Solaris 2.6.

Table 2. Examples of Device Special File Names

If the logical file name is: The device special file name is:
3mt /dev/rmt/3mt
0lb /dev/rmt/0lb
1op /dev/rmt/1op
2st Drive: /dev/rmt/2st

Medium changer: /dev/rmt.2smc (3570 or 3590 B11 with ACF)

Attaching the Devices

Ensure that your devices are physically attached to your system according to the manufacturer's instructions.

Attaching Drives in a Manual Library

Here is an overview of the procedure for attaching a drive in a manual library to the server system:

  1. Install the SCSI adapter card in your system, if one is 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.
  3. 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.
    Note: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 driver.
  6. Determine the name for the device, which is needed to define the device to TSM. See Determining Device Names for Tivoli Storage Manager.

Attaching an Autochanger and its Drives

Here is an overview of the procedure for attaching an automated library to the server system:

  1. Ensure that the SCSI adapter card is installed in your system.
  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.
    Note: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 page"Attaching the Devices".
  6. Find the device worksheet that applies to your device. See the device configuration worksheets appendix in the Administrator's Guide.
  7. Determine the name for each device, which is needed to define the device to TSM, and record the name on the device worksheet.

    The device name for each drive has the form /dev/rmt/xmt. The device name for the library controller has the form /dev/rmt/xlb. 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.

Setting the Library Mode

For TSM to access a SCSI library, the device must be set for the appropriate mode. The mode that TSM requires is usually called random mode; however, terminology may vary from one device to another. Two examples follow:

Refer to the documentation for your device to determine how to set it to a mode appropriate for TSM.

Installing Device Drivers

This section describes how to install the available device drivers.

Installing Device Drivers for IBM 3490, 3570, and 3590 Tape Drives

For IBM 3490, 3570, and 3590 devices, see IBM SCSI Device Drivers: Installation and User's Guide for how to install the device drivers.

After completing the procedure in the manual, a set of special file names are available for each device. To see the special file names, use the command

+--------------------------------------------------------------------------------+
|ls -la /dev/rmt                                                                 |
+--------------------------------------------------------------------------------+

The output shows that the special files are really symbolic links into the /devices tree of the file system.

Installing Device Drivers for IBM 349X Libraries

For an IBM 3494 Tape Library Dataserver, use the information in IBM SCSI Device Drivers: Installation and User's Guide to install the driver. The driver is the IBM Tape Library Driver for Sun Solaris, which consists of the lmcpd (a daemon) and other components.

To determine the name to use to define the library to TSM, check what you entered in the /etc/ibmatl.conf file for the library's symbolic name. Use this information to complete the Device Name field on your worksheet.

For example, if the symbolic name for the library in the /etc/ibmatl.conf file is 3494a, enter that name on the worksheet in the Device Name field for the library.

The drives that are in the library are set up separately. See Installing Device Drivers for IBM 3490, 3570, and 3590 Tape Drives.

Installing Device Drivers for Non-IBM Tape Drives and Libraries

To use the TSM device drivers, you must do the following:

  1. Have installed the TSM device driver package (TIVsmSdev). See Installing Tivoli Storage Manager for details.
  2. Edit configuration files that reside in the /usr/kernel/drv directory, and then issue the add_drv (add drive) command. The devices should already be connected to the system and powered on.

If you are configuring a tape library, you must set up the device drivers for both the drives in the library and the library itself (that is, the robotics).

Installing the Tivoli Storage Manager Device Driver for Tape Drives

To install the Tivoli Storage Manager device driver for tape drives, perform the following steps:

  1. Verify that the device is connected to your system, and is powered on and active.
  2. Edit the /usr/kernel/drv/mt.conf file. Add one stanza (as shown in the example at the top of the file) for each TSM tape drive in the system that you want the Tivoli Storage Manager server to use.
  3. Log in as root user.
  4. Add the drive by entering the following command:
    +--------------------------------------------------------------------------------+
    |> /usr/sbin/add_drv -m '* 0666 bin bin' /usr/kernel/drv/mt                      |
    +--------------------------------------------------------------------------------+
  5. Determine the special file names for the tape drives.

    The device special files for the tape drives appear in the /dev/rmt directory. Their names have the form /dev/rmt/xmt, where x is a number. To determine the relationship between a physical device and the special file that was created for it, issue the following command:

    +--------------------------------------------------------------------------------+
    |> ls -l /dev/rmt/*mt                                                            |
    +--------------------------------------------------------------------------------+

    The output shows that the special file is really a symbolic link into the /devices tree of the file system. The symbolic link destination has the form /devices/.../mt@x,0:mt, where x is the SCSI ID of the device. This information lets you know which of the /dev/rmt/xmt special file names to provide to the server when you issue a DEFINE DRIVE command.

  6. Record the SCSI IDs and special file names on your worksheets. See the device configuration worksheets appendix in the Administrator's Guide.

Installing the Tivoli Storage Manager Device Driver for Tape Libraries

To install the Tivoli Storage Manager device driver for tape libraries, perform the following steps:

  1. Edit the /usr/kernel/drv/lb.conf file. Add one stanza (as shown in the example at the top of the file) for each TSM autochanger device in the system that you want the Tivoli Storage Manager server to use.
  2. Log in as root user.
  3. Add the library by entering the following command:
    +--------------------------------------------------------------------------------+
    |> /usr/sbin/add_drv -m '* 0666 bin bin' /usr/kernel/drv/lb                      |
    +--------------------------------------------------------------------------------+
  4. Determine the special file names for the tape libraries.

    The device special files for libraries appear in the /dev/rmt directory. Their names have the form /dev/rmt/xlb, where x is a number. To determine the relationship between a physical device and the special file that was created for it, issue the following command:

    +--------------------------------------------------------------------------------+
    |> ls -l /dev/rmt/*lb                                                            |
    +--------------------------------------------------------------------------------+

    The output shows that the special file is really a symbolic link into the /devices tree of the file system. The symbolic link destination has the form /devices/.../lb@x,y:lb, where x is the SCSI ID of the device and where y is the LUN (logical unit number) of the device. This information lets you know which of the /dev/rmt/xlb special file names to provide to the server when you issue a DEFINE LIBRARY command.

  5. Record the SCSI IDs and special file names on your worksheets. See the device configuration worksheets appendix in the Administrator's Guide.

Installing Device Drivers for Optical Devices

To use the TSM device drivers, you must first edit configuration files that reside in the /usr/kernel/drv directory, and then issue the add_drv (add drive) command. The devices should already be connected to the system and powered on.

If you are configuring a tape library, you must set up the device drivers for both the drives in the library and the library itself (that is, the robotics) for TSM to use.

Installing the Tivoli Storage Manager Device Driver for Optical Drives

To install the Tivoli Storage Manager device driver for optical drives, perform the following steps:

  1. Verify that the device is connected to your system, and is powered on and active.
  2. Edit the /usr/kernel/drv/op.conf file. Add one stanza (as shown in the example at the top of the file) for each TSM tape drive in the system that you want the TSM server to use.
  3. Log in as root user.
  4. Add the drive by entering the following command:
    +--------------------------------------------------------------------------------+
    |/usr/sbin/add_drv -m '* 0666 bin bin' /usr/kernel/drv/op                        |
    +--------------------------------------------------------------------------------+
  5. Determine the special file names for the drives.

    The device special files for the optical drives appear in the /dev/rmt directory. Their names have the form /dev/rmt/xop, where x is a number. To determine the relationship between a physical device and the special file that was created for it, issue the following command:

    +--------------------------------------------------------------------------------+
    |ls -l /dev/rmt/*op                                                              |
    +--------------------------------------------------------------------------------+

    The output shows that the special file is really a symbolic link into the /devices tree of the file system. The symbolic link destination has the form /devices/.../op@x,0:op, where x is the SCSI ID of the device. This information lets you know which of the /dev/rmt/xop special file names to provide to the server when you issue a DEFINE DRIVE command.

  6. Record the SCSI IDs and special file names on the worksheets.

Installing the Tivoli Storage Manager Device Driver for Optical Libraries

To install the Tivoli Storage Manager device driver for a library, perform the following steps:

  1. Edit the /usr/kernel/drv/lb.conf file. Add one stanza (as shown in the example at the top of the file) for each TSM autochanger device in the system that you want the Tivoli Storage Manager server to use.
  2. Log in as root user.
  3. Add the library by entering the following command:
    +--------------------------------------------------------------------------------+
    |> /usr/sbin/add_drv -m '* 0666 bin bin' /usr/kernel/drv/lb                      |
    +--------------------------------------------------------------------------------+
  4. Determine the special file names for the tape libraries.

    The device special files for libraries appear in the /dev/rmt directory. Their names have the form /dev/rmt/xlb, where x is a number. To determine the relationship between a physical device and the special file that was created for it, issue the following command:

    +--------------------------------------------------------------------------------+
    |> ls -l /dev/rmt/*lb | grep lb@                                                 |
    +--------------------------------------------------------------------------------+

    The output shows that the special file is really a symbolic link into the /devices tree of the file system. The symbolic link destination has the form /devices/.../lb@x,y:lb, where x is the SCSI ID of the device and where y is the LUN (logical unit number) of the device. This information lets you know which of the /dev/rmt/xlb special file names to provide to the server when you issue a DEFINE LIBRARY command.

  5. Record the SCSI IDs and special file names on your worksheets. See the device configuration worksheets appendix in the Administrator's Guide.

Adding a Manual Tape Library

In the following example, two stand-alone 8mm drives are added to Tivoli Storage Manager. Because an operator must mount tapes for these drives, you must define them as part of a manual library to TSM. 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.

The commands, in the order entered, for defining a manual tape library are:
DEFINE LIBRARY
DEFINE DRIVE
DEFINE DEVCLASS
DEFINE STGPOOL

  1. Define a manual library and two drives associated with it. The library is named MANUALLIB. The two drives, named DRIVE01 and DRIVE02, are at SCSI adaptor 0 and SCSI IDs 1 and 2.


    Admin Command Line

    +--------------------------------------------------------------------------------+
    |define library manuallib libtype=manual                                         |
    |define drive manuallib drive01 device=/dev/rmt/1mt                              |
    |define drive manuallib drive02 device=/dev/rmt/2mt                              |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Server Storage.
    2. Expand Libraries and Drives.
    3. Select Manual Libraries.
    4. From Operations, select Define Manual Library.
    5. Enter the library information and Finish.
    6. Under Libraries and Drives, select Manual Drives.
    7. From Operations, select Define Manual Drive.
    8. Enter the drive information and Finish.
  2. Classify the devices by device type. It is helpful to choose a device class name that identifies the type of device for which it is intended (in this example, TAPECLASS).


    Admin Command Line

    +--------------------------------------------------------------------------------+
    |define devclass tapeclass devtype=8mm -                                         |
    |  format=8500 library=manuallib                                                 |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Device Classes.
    2. Select 8MM Device Classes.
    3. From Operations, select Define Device Class.
    4. Enter the device class information and Finish.
  3. Define a storage pool named TAPEPOOL for the device class.
    Admin Command Line
    +--------------------------------------------------------------------------------+
    |define stgpool tapepool tapeclass maxscratch=20                                 |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Server Storage.
    2. Expand Storage Pools.
    3. Select Sequential Access Storage Pools.
    4. From Operations, select Define Sequential Access Storage Pool.
    5. Enter the storage pool information and Finish.

Adding an Automated Tape Library

For the following example, an Exabyte EXB-210 library containing two drives is added to TSM. 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.

The commands, in the order entered, for defining an automated tape library are:
DEFINE LIBRARY
DEFINE DRIVE
DEFINE DEVCLASS
DEFINE STGPOOL

  1. Define an automated tape library and its two internal drives.

    The library is an Exabyte EXB-210, named AUTOLIB, whose SCSI library mechanism is at SCSI ID 3. The two drives, named DRIVE05 and DRIVE06, are at SCSI IDs 5 and 6. The element addresses for the drives in an EXB-210 are 82 and 83.


    Admin Command Line

    +--------------------------------------------------------------------------------+
    |define library autolib libtype=scsi device=/dev/rmt/3lb                         |
    |define drive autolib drive05 device=/dev/rmt/5mt element=82                     |
    |define drive autolib drive06 device=/dev/rmt/6mt element=83                     |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Server Storage.
    2. Expand Libraries and Drives.
    3. Select Automated Libraries.
    4. From Operations, select Define Automated Library.
    5. Enter the library information and Finish.
    6. Under Libraries and Drives, select Automated Drives.
    7. From Operations, select Define Automated Drive.
    8. Enter the drive information and Finish.


    A Closer Look

    Element address

    The element address is a number that indicates the physical location of a drive within an automated library. TSM 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.

  2. Classify the drives in the library by device type. It is helpful to choose a device class name that identifies the type of device for which it is intended (in this example, AUTOCLASS).


    Admin Command Line

    +--------------------------------------------------------------------------------+
    |define devclass autoclass devtype=8mm -                                         |
    | format=8500 library=autolib                                                    |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Device Classes.
    2. Select 8MM Device Classes.
    3. From Operations, select Define Device Class.
    4. Enter the device class information and Finish.
  3. Define a storage pool named AUTOPOOL for the device class.
    Admin Command Line
    +--------------------------------------------------------------------------------+
    |define stgpool autopool autoclass maxscratch=20                                 |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Storage Pools.
    2. Select Sequential Access Storage Pools.
    3. From Operations, select Define Sequential Access Storage Pool.
    4. Enter the storage pool information and Finish.

Displaying Information About Your Devices

Before continuing, you can view the results of your definitions. If necessary, you can update these definitions by using update commands.


Admin Command Line

OR
Web Icon

Preparing Tape Volumes

All tape volumes must be labeled before TSM can use them. If you want a volume to be used only when it is requested by name, you must also define it to TSM. A defined volume is a private volume and is assigned to a specific storage pool. A volume that is not defined to TSM is a scratch volume. A storage pool can request available scratch volumes up to the number specified for that storage pool.

Preparing Tape Volumes with a Manual Drive

If you are using only one tape drive, consider labeling several tapes at this time.

  1. From an TSM administrative client command line, use a drive in the library named MANUAL to label a volume as DSM001:
    Admin Command Line
    +--------------------------------------------------------------------------------+
    |                                                                                |
    |label libvolume manual dsm001                                                   |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Server Storage.
    2. Expand Libraries and Drives.
    3. Select Library Volumes.
    4. From Operations, select Label Library Volume.
    5. Enter the volume information and Finish.
  2. Define any volumes that are to be used as private volumes. For example, define the volume you just labeled:
    Admin Command Line
    +--------------------------------------------------------------------------------+
    |                                                                                |
    |define volume tapepool dsm001                                                   |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Storage Pools.
    2. Select Sequential Access Storage Pools.
    3. Select the storage pool you want.
    4. Select Volumes.
    5. From Operations, select Define Sequential Access Volume.
    6. Enter the volume information and Finish.

Preparing Tape Volumes with an Automated Library

To label tapes with an automated library, remove any tapes that you do not want to use with TSM and load the tapes to be labeled.

  1. Use the LABEL LIBVOLUME command to label and check in the volumes. From an administrative client command line, begin a search of an automated library named AUTOLIB for unlabeled volumes and label them based on their barcodes:
    Admin Command Line
    +--------------------------------------------------------------------------------+
    |label libvolume autolib search=yes labelsource=barcode                          |
    |  checkin=scratch                                                               |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Server Storage.
    2. Expand Libraries and Drives.
    3. Select Library Volumes.
    4. From Operations, select Label Library Volume.
    5. Enter the volume information and Finish.
  2. Define any volumes that are to be used as private volumes.
    Admin Command Line
    +--------------------------------------------------------------------------------+
    |                                                                                |
    |define volume autopool dsm001                                                   |
    +--------------------------------------------------------------------------------+

    OR
    Web Icon

    1. Expand Storage Pools.
    2. Select Sequential Access Storage Pools.
    3. Select the storage pool you want.
    4. Select Volumes.
    5. From Operations, select Define Sequential Access Volume.
    6. Enter the volume information and Finish.

Including Tape in the Storage Hierarchy

You can now configure TSM so that client data can be migrated to tape. To migrate from BACKUPPOOL to AUTOPOOL and from ARCHIVEPOOL to TAPEPOOL do the following:


Admin Command Line

+--------------------------------------------------------------------------------+
|update stgpool backuppool nextstgpool=autopool                                  |
|update stgpool archivepool nextstgpool=tapepool                                 |
+--------------------------------------------------------------------------------+
OR
Web Icon
  1. Expand Server Storage.
  2. Expand Storage Pools.
  3. Select Disk Storage Pools.
  4. Select the pool to be updated.
  5. Select Update Disk Storage Pool.
  6. Enter the storage pool information and Finish.

Migrating Data from Disk to Tape

To verify that the tape devices are properly set up, migrate data from a disk storage pool. Migration requires tape mounts. The mount messages are directed to the console message queue and to any administrative client that has been started with either the mount mode or console mode option.

Trigger migration from a disk storage pool (BACKUPPOOL, for example) by setting the high and low migration thresholds to 0:
Admin Command Line

+--------------------------------------------------------------------------------+
|update stgpool backuppool highmig=0 lowmig=0                                    |
+--------------------------------------------------------------------------------+

After migration occurs, reset the thresholds to their original settings:

+--------------------------------------------------------------------------------+
|update stgpool backuppool highmig=90 lowmig=70                                  |
+--------------------------------------------------------------------------------+
OR

To migrate data from a disk storage pool and, after migration occurs, to reset the thresholds to their original settings, update the storage pool:
Web Icon

  1. Expand Server Storage.
  2. Expand Storage Pools.
  3. Select Disk Storage Pools.
  4. Select the pool to be updated.
  5. Select Update Disk Storage Pool.
  6. Enter the storage pool information and Finish.


A Closer Look

Controlling when migration occurs

Because migration from a disk to a tape storage pool uses resources such as drives and operators, you may want to control when migration occurs. To do so, leave the high migration threshold set to 100 most of the time, and lower it when you want migration to occur.

In the preceding step, you lowered both migration thresholds to 0 to verify that migration occurred. You may not want to empty the disk storage pool by setting the low migration threshold to 0 every time you want migration to occur. Normally, you may want to keep the low threshold at 40%, and vary the high threshold from as high as 90% to as low as 50%. See Administrator's Guide for details.


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