Create FlashCopy Logical Drive Wizard: Additional Instructions for AIX - LVM Logical Logical Drives

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Use the following procedure when creating FlashCopy logical drives on a host running AIX 4.3.3 (or higher), using LVM Logical Logical Drives. Failure to complete the steps listed may result in an inaccurate point-in-time image of the base logical drive.

Caution: The following restrictions apply when attempting to create FlashCopy logical drives on AIX:

For a process overview of the FlashCopy logical drive creation process, refer to Create FlashCopy Logical Drive Wizard: Process Overview - Unix with Logical Drive Manager Logical Drives.

FlashCopy logical drives may be reused (for frequent or nightly backups) or may be created for one-time usage (for speculative change or upgrade testing). For instructions on how to reuse a disabled FlashCopy logical drive, see Reusing FlashCopy Logical Drives.

How to Create a FlashCopy Logical Drive

Important: All I/O activity to the base logical drive should be stopped at this point (or data transfer suspended). This will ensure that an accurate point-in-time image of the base logical drive is captured.

1

Locate the array (on which the FlashCopy logical drive is to be based) and unmount its associated filesystems.

At the host prompt, type the following, then press Enter:

umount mount-point

where mount-point is the name of the filesystem being unmounted.

2

Start the storage management software.

Result: The Enterprise Management Window is displayed.

3

Launch an Subsystem Management Window using one of the following methods:

  • Select the storage subsystem in either the Device Tree View or the Device Table, then select the Manage Device toolbar button, or the Tools >> Manage Device pull-down menu option.
  • Right-click the storage subsystem in the Device Tree View or Device Table, then select Manage Device from the right-mouse pop-up menu.
  • Double-click on a storage subsystem node in the Device Table.
  • Select the storage subsystem in either the Device Tree View or the Device Table, then press Enter.

Result: The Subsystem Management Window is opened in a separate window.

4

Important: If an AIX array has more than one logical drive, FlashCopy logical drives must be created for each of the logical drives in the array.

Within the Logical View of the Subsystem Management Window, select a standard logical drive and create a FlashCopy logical drive using one of the following methods:

  • Create FlashCopy Logical Drive Wizard, accessed using an Subsystem Management Window. For more information, see Creating a FlashCopy Logical Drive Using the FlashCopy Logical Drive Wizard.
  • Create a FlashCopy logical drive using either the Script Editor or a command line shell on the host operating system. Type the following command and press Enter:

    create FlashCopyLogicalDrive

    For command reference information on creating a FlashCopy logical drive, refer to "Using the create Command" in the Enterprise Management Window online help.

5

Assign a logical drive-to-LUN mapping between the FlashCopy logical drives and the host that will access the FlashCopy logical drives.

Logical Drive-to-LUN mappings can be defined using one of the following methods:

  • Storage Partitioning Wizard. The Storage Partitioning Wizard helps you to quickly define a single storage partition. It guides you through the major steps required to specify which host will access a logical drive and the associated Logical Unit Numbers. For more information, see Using the Storage Partitioning Wizard.
  • Create a logical drive-to-LUN mapping using either the Script Editor or a command line shell on the host operating system. Type the following command and press Enter:

    create mapping logical drive

    For command reference information on creating a logical drive-to-LUN mapping, see "Using the create Command" in the Enterprise Management Window online help.

6

Login to the host as root.

7

Run the hot_add utility (or an operating-system specific utility) to ensure that the host operating system recognizes the FlashCopy logical drives.

To use hot_add, at the host prompt, type the following command and then press Enter:

hot_add

Several minutes may pass while the computer is accessing the drives. When the program is finished, a screen is displayed with the following:

Device nodes have been updated

The new logical drives should now be available to you through the operating system.

8

Run the SMdevices utility to associate the LUNs with a host operating system device and to ensure that the logical drive name and the operating system device name (assigned by the operating system) correlate.

Look for the newly created FlashCopy logical drive names and note the names of the associated operating system device name. For example, you created a FlashCopy logical drive named accountingMay14 and it's associated operating system device name is hdisk4.

9

At the host prompt, type the following, then press Enter:

lspv

Result: A list of all the physical logical drives recognized by the host operating system is displayed.

10

Look for the operating system device name of your FlashCopy logical drive or logical drives in the list. The listing will show a Physical Logical Drive ID (PVID) for this logical drive that will be the same as the PVID for the associated base logical drive. This is because the FlashCopy logical drive contains the same array data structures as the base logical drive.

11

Clear the PVID for the FlashCopy logical drives. At the host prompt, type the following, then press Enter:

chdev - l os_device_name -a pv=clear

where os_device_name is the operating system device name of the FlashCopy logical drive. Repeat for each FlashCopy logical drive in the AIX array.

12

Recreate a new array. The recreatevg command, available in usr/sbin/, reads the array data structure inside a logical drive and reconstructs it. The command will allocate new physical logical drive identifiers (PIDs) to the FlashCopy logical drives and enable access to the FlashCopy logical drive for the selected host.

Important: If this command is not available in AIX 4.3.3., install the AIX version 4.3.3 Recommended Maintenance Level 06 (AIX 4330-06) maintenance package.

At the host prompt, type the following, then press Enter:

recreatevg -y logical drivegroupname -L /directoryname os_device_name

  • where logical drivegroupname is the user-defined name to be assigned to the FlashCopy array.
  • where directoryname is the name of the directory where you want to mount the FlashCopy logical drive.
  • where os_device_name is the operating system device name of the FlashCopy logical drive. If your AIX array will be made up of more than one FlashCopy logical drive, add an os_device_name for each logical drive.

Result: The array is recreated and contains the FlashCopy logical drive or logical drives.

13

Mount the filesystem to its intended host. At the host prompt, type the following, then press Enter:

mount mount-point

where mount-point is the name of the filesystem being mounted. Include the directoryname used in step 12.

14

Ensure that the logical logical drives are back online. At the host prompt, type the following, then press Enter:

df -k

Result: A list of the mounted disks is displayed.

15

Use the FlashCopy logical drive in conjunction with your backup application, for speculative testing, or with another application.

16

When the FlashCopy logical drive is no longer required, unmount the filesystem. At the host prompt, type the following, then press Enter:

umount mount-point

where mount-point is the name of the filesystem being unmounted.

17

Delete the array created in step 12 that contains the FlashCopy logical drives. At the host prompt, type the following, then press Enter:

varyoffvg logical drivegroupname

exportvg logical drivegroupname

where logical drivegroupname is the name of the FlashCopy array.

18

Disable or delete the FlashCopy logical drive or logical drives.

If you disable the FlashCopy logical drive instead of deleting it, you can retain the FlashCopy logical drive and its associated repository logical drive. 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 takes less time than creating a new FlashCopy logical drive and will stop any reduction in performance that may occur if the FlashCopy logical drive remains available.

For information on disabling or recreating a FlashCopy, see Disabling a FlashCopy Logical Drive and Re-creating a FlashCopy Logical Drive. For information on deleting a FlashCopy logical drive, see Deleting a Logical Drive.

For command reference information on disabling, re-creating, and deleting a FlashCopy logical drive, refer to the Enterprise Management Window online help.

Reusing FlashCopy Logical Drives

Typically, once a FlashCopy logical drive has been created, it would be disabled until a new point-in-time image of the same base logical drive is required. To create a new point-in-time image of the same base logical drive, complete the following steps.

Important: All I/O activity to the base logical drive should be stopped at this point (or data transfer suspended). This will ensure that an accurate point-in-time image of the base logical drive is captured.

1

Unmount the filesystems in the array on which the FlashCopy logical drive is to be based.

At the host prompt, type the following, then press Enter:

umount mount-point

where mount-point is the name of the filesystem being unmounted.

2

Run the hot_add utility (or an operating-system specific utility) to ensure that the host operating system recognizes the FlashCopy logical drive.

To use hot_add, at the host prompt, type the following command and then press Enter:

hot_add

Several minutes may pass while the computer is accessing the drives. When the program is finished, a screen is displayed with the following:

Device nodes have been updated

The new logical drives should now be available to you through the operating system.

3

In the storage management software, re-create the FlashCopy logical drives using one of the following methods:

  • Select the Logical Drive >> FlashCopy >> Re-create pull-down menu option in the Subsystem Management Window. For more information see Re-creating a FlashCopy Logical Drive.
  • Re-create a FlashCopy logical drive using either the Script Editor or a command line interface on the host operating system. Type the following command and press Enter:

    recreateFlashCopy logical drive

    For command reference information on re-creating a FlashCopy logical drive, see "Using the recreateFlashCopy Command" in the Enterprise Management Window online help.

4

Clear the PVID for the FlashCopy logical drives. At the host prompt, type the following, then press Enter:

chdev - l os_device_name -a pv=clear

where os_device_name is the operating system device name of the FlashCopy logical drive. Repeat for each FlashCopy logical drive in the AIX array.

5

Recreate a new array. The recreatevg command, available in usr/sbin/, reads the array data structure inside a logical drive and reconstructs it. The command will allocate new physical logical drive identifiers (PIDs) to the FlashCopy logical drives and enable access to the FlashCopy logical drive for the selected host.

Important: If this command is not available in AIX 4.3.3., install the AIX version 4.3.3 Recommended Maintenance Level 06 (AIX 4330-06) maintenance package.

At the host prompt, type the following, then press Enter:

recreatevg -y logical drivegroupname -L /directoryname os_device_name

  • where logical drivegroupname is the user-defined name to be assigned to the FlashCopy array.
  • where directoryname is the name of the directory where you want to mount the FlashCopy logical drive.
  • where os_device_name is the operating system device name of the FlashCopy logical drive. If your AIX array will be made up of more than one FlashCopy logical drive, add an os_device_name for each logical drive.

Result: The array is recreated and contains the FlashCopy logical drive or logical drives.

6

Mount the filesystem to its intended host. At the host prompt, type the following, then press Enter:

mount mount-point

where mount-point is the name of the filesystem being mounted. Include the directoryname used in step 5.

7

Ensure that the logical logical drives are back online. At the host prompt, type the following, then press Enter:

df -k

Result: A list of the mounted disks is displayed.

8

Use the FlashCopy logical drive in conjunction with your backup application (or another application).

9

Once the FlashCopy 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 repository logical drive. 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 takes less time than creating a new FlashCopy logical drive and will stop any reduction in performance that may occur if the FlashCopy logical drive remains available.

For more information, see Disabling a FlashCopy Logical Drive and Re-creating a FlashCopy Logical Drive. For command reference information on disabling and re-creating a FlashCopy logical drive, refer to the Enterprise Management Window online help.

Related Topics

Create FlashCopy Logical Drive Wizard: Additional Instructions

Learn About Creating FlashCopy Logical Drives

Creating a FlashCopy Logical Drive Using the FlashCopy Wizard