Reusing FlashCopy Logical Drives: Additional Information for AIX – LVM Logical Volumes

Typically, after a has been created, it would be disabled until a new point-in-time image of the same is required. Create a new point-in-time image of the same base logical drive.


Important:

If the recreatevg command is not available in the AIX 4.3.3 operating system, install the AIX 4.3.3 operating system, with the Recommended Maintenance Level 06 (AIX 4330-06) maintenance package.

  1. Stop all activity to the base logical drive at this point (or data transfer suspended). This action makes sure that an accurate point-in-time image of the base logical drive is captured.
  2. Unmount the file systems in the array on which the flashcopy logical drive is to be based. At the host prompt, type this command, and press Enter:

    umount mount-point
    

    In this command, mount-point is the name of the file system being unmounted.

  3. Run the (or an operating-system specific utility) to make sure that the host operating system recognizes the flashcopy logical drive. At the host prompt, type this command, and press Enter:

    hot_add
    

    Several minutes might elapse while the computer is accessing the disk drives. When the program is finished, a dialog appears with this message:

    Storage Subsystem nodes have been updated
    The new logical drives are now available to you through the operating system.
  4. In the storage management software, re-create the flashcopy logical drives by using one of these methods:

    recreateflashcopy volume
    

    For command reference information about re-creating a flashcopy logical drive, refer to the online help topics in the Enterprise Management Window.

  5. Clear the PVID for the flashcopy logical drives. At the host prompt, type this command, and press Enter:

    chdev - l os_device_name -a pv=clear
    

    In this command, os_device_name is the name of the flashcopy logical drive in the operating system. Repeat this step for each flashcopy logical drive in the AIX array.

  6. Re-create a new array. At the host prompt, type this command, and press Enter:

    recreatevg -y volume-group-name -L /directory-name os-device-name
    

    In this command, volume-group-name is the user-defined name to be assigned to the flashcopy array., directory-name is the name of the directory where you want to mount the flashcopy logical drive, and os-device-name is the storage subsystem name of the flashcopy logical drive in the operating system. If your AIX array is made up of more than one flashcopy logical drive, add an os-device-name for each logical drive.

    Thearray is re-created and contains the flashcopy logical drive or logical drives.

    The recreatevg command, which is available in the usr/sbin/ directory, reads the array data structure inside a logical drive and reconstructs it. The command allocates new PVIDs to the flashcopy logical drives and enables access to the flashcopy logical drive for the selected host.

  7. Mount the file system to its intended host. At the host prompt, type this command, and press Enter:

    mount mount-point
    

    In this command, mount-point is the name of the file system being mounted. Include the directory-name that was used in step 6.

  8. Make sure that the logical logical drives are back online. At the host prompt, type this command, and press Enter:

    df -k
    

    A list of the mounted disks appears.
  9. Use the flashcopy logical drive with your backup application (or another application).
  10. When theflashcopy logical drive is no longer required, disable the flashcopy logical drive.

    If you disable the flashcopy logical drive instead of deleting it, you can retain the flashcopy logical drive and its associated . Then, when you need to create a different flashcopy of the same base logical drive, you can re-create the disabled flashcopy logical drive. This action takes less time than creating a new flashcopy logical drive and stops any reduction in performance that might occur if theflashcopy logical drive remains available.

    For more information, refer to the Disabling a FlashCopy Logical Drive online help topic and the Re-creating a FlashCopy Logical Drive online help topic.

    For command reference information about disabling and re-creating a flashcopy logical drive, refer to the online help topics in the Enterprise Management Window.

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