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Setting up external volumes

You set up ports and external paths, map external volumes, and then begin using them with native storage on your storage system. This chapter describes external volume setup procedures and information, including configuring ports and port attributes, mapping external volumes, preparing mapped volumes for use, and using mapped volumes. It also discusses recognizing the local system from the external system.

Workflow for setting up external volumes

You must complete all planning and preparation tasks before setting up Universal Volume Manager.

Before you begin setting up Universal Volume Manager, consult the topics in Planning workflow to make sure you have completed all planning tasks.

  1. Set up ports. For details, see Setting up ports .
  2. [Optional] Edit mapping settings before starting the mapping operation. For details, ee External volume policy settings and functions.

    You can also make changes during the mapping operation or accept the default settings.

  3. Map each external volume to an internal volume.

    For details, see Mapping an external volume .

  4. After an external volume is successfully mapped, use LUN Manager to define LU paths to hosts. For details, see the Provisioning Guide.

Setting up ports

When you connect external storage systems to a port, information on those storage systems can be viewed from client computers. Multiple external storage systems from different vendors can be connected to the same port. Even if a port connected to external storage systems is in use, you can connect additional external storage systems.

Limitations on mapping an external volume

You must set the port attribute to External port before you can map the external volume as an internal volume. Make sure to check the capacity requirements of the external volume you intend to map as an internal volume.

Following are the limitations on mapping an external volume:

  • You cannot access data that is stored in an area that exceeds the maximum capacity of the external volume. For example, if you map 100 GB of an external volume as 70 GB of the internal volume, 30 GB of the external volume cannot be accessed from the local storage system side.
  • You cannot map an external volume which does not meet the minimum capacity requirement. For example, you cannot map 10 GB of the external volume as an internal volume with a minimum capacity requirement of 30 GB.
  • Volumes for which the T10 PI attribute is enabled cannot be specified as an external volume.

Mapping an external volume

Set the attribute of the port used for Universal Volume Manager to the external port, and then you can map the external volume as an internal volume.

Before you begin

  • You must have the Storage Administrator (Provisioning) role.
  • Attributes set for the external volume before mapping, such as port security, LUN security, Volume Retention Manager attributes are discarded when the external volume is mapped. If the original attributes are required, reset them in the local storage system after mapping.
  • Volumes for which the T10 PI attribute is enabled cannot be specified as an external volume.
  • When the external volume is a command device, it is mapped as a remote command device. For important information about mapping command devices, see Using a remote command device.
  • Before you map the external volume, determine whether any application is using the volume. If you find any, stop them before mapping.

    For example, before mapping a command device, make sure CCI commands are not being run.


When you create an LDEV at the same time that you map an external volume, you cannot select the following LDEV numbers:

  • Numbers already in use.
  • Numbers not assigned to the user.


  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click Add External Volumes.

  3. In the Add External Volumes window, select an existing path group or create a new one.

    To create an external path group, select By New External Path Group, click Create External Path Group, specify the following, and then click OK:
    • Initial External Path Group ID: The storage system searches IDs from the initial ID you specify in ascending order and allocates an ID that can be used. The default is 0. Specify a value in the following range: 0 to 63,231

    • External Paths: If the port or WWN/iSCSI target name you want is not in the Available External Paths table, click Discover External Target Ports, add ports, and then click OK.

    • External Storage System: Select the desired external storage system.

    • Available External Paths: Select the desired port IDs, and then click Add.

    • Set the priority for a path by selecting it, and then clicking Raise Priority or Lower Priority.
    To use an existing external path group, select By Existing External Path Group, and then select the desired path group from the Available External Paths table.
  4. Click Next.

  5. In the Discovered External Volumes table, select the desired external volumes.

  6. In Initial Parity Group ID, enter an external volume group number and sequential number. You can use the group number to place similar external volumes in a group. For example, you could assign the same external volume group number to volumes used for a copy function.

    • The range is from 1 - 1 to 16384 - 4096.
    • To map an external volume with more than 4 TB by using a virtual volume for which Data Direct Mapping is enabled, select Enable in Data Direct Mapping. When you do, Yes is automatically selected for Allow Simultaneous Creation of LDEVs and Use External Storage System Configuration.

      For details about mapping using virtual volumes for which Data Direct Mapping is enabled, see the Provisioning Guide.

  7. Specify Allow Simultaneous Creation of LDEVs.

    • To allow the system to automatically create LDEVs in the external volume, select Yes. To manually create LDEVs, select No.
    • If the external volume is a command device, select Yes for both Allow Simultaneous Creation of LDEVs and Use External Storage System Configuration.
  8. Specify Use External Storage System Configuration.

    • If you select Yes, Base Emulation Type is disabled and the emulation type is set based on the LDEV name of the external storage system.
    • If you select No, Base Emulation Type is enabled so you can select the type.
    • If you select Yes in both Allow Simultaneous Creation of LDEVs and Use External Storage System Configuration, one LDEV with the same capacity as the OPEN-V external volume will be created.
    • If you select Disable in Data Direct Mapping and the external volume is larger than 4 TB, one 4 TB LDEV will be created.
  9. In LDEV Name, enter the prefix character and the initial number.

    If you enter a prefix character and an initial number, their combined value can be a maximum of 32 characters, including the initial number (numerical value of 9 digits or less). Note the following numbering rule:
    • 1: Total of 9 numbers (1, 2, 3, ...9)
    • 08: Total of 92 numbers (08, 09, 10, ...99)
    • 23: Total of 77 numbers (23, 24, 25, ...99)
    • 098: Total of 902 numbers (098, 099, 100, ...999)
  10. Click Options (if not already expanded). If you have previously edited mapping settings (policies), you might not want to change the options. However, review the following steps, because some fields in Options are affected by the preceding steps.

  11. In the expanded Options box, for Initial LDEV ID enter the initial LDEV ID for the external volume. The local storage system searches from this number in ascending order and allocates the next available ID. You can review used, available, and disabled LDEVS by clicking View LDEV IDs.

    • For LDKC, enter 00.
    • For CU, enter the CU number. The default is 00. Specify a value in the following range:

      - VSP G350, VSP F350: 00 to 3F

      - VSP G370, VSP F370: 00 to 7F

      - VSP G700, VSP F700: 00 to BF

    • For DEV, enter the LDEV ID, which can be from 00 to FF. The default is 00.
    • For Interval, enter an interval between LDEV IDs, which can be from 0 to 255. The default is 0.
  12. In Number of LDEVs per External Volume, enter the number of LDEVs to be created when the volume is mapped. This field is greyed out if you selected Yes in Allow Simultaneous Creation of LDEVs and Use External Storage System Configuration, and 1 displays.

  13. In Cache Partition, select the CLPR for accessing the mapped external volume.

    NoteFor more information about the Cache Partition, Cache Mode, and Inflow Control settings, see External volume policy settings and functions.
  14. In Cache Mode, select Enable to propagate write data asynchronously from cache to the external storage system. Select Disable to propagate data synchronously.

    • When the external volume is a command device, Cache Mode for the remote command device is automatically set to Disable regardless of your setting.
    • Data that is not written by the host (for example, data written by pair operation) is asynchronously destaged to the external storage system regardless of the Cache Mode setting.
  15. In Inflow Control, select Enable to limit or prevent write data from being written to cache memory when the write operation to the external volume cannot be performed. Select Disable to allow write data to be written to cache.

  16. In MP Unit ID, select the MP unit for the external volume, making sure to assign them so that work is evenly distributed across the available processors.

    To automatically assign an MP unit, select Auto (the default). If Auto is not available, the MP unit with the lowest number is selected by default. Otherwise, select one of the following values:

    • VSP G350, G370, G700, G900, VSP F350, F370, F700, F900: MPU-10 or MPU-20
    • VSP G1x00, VSP F1500: MPB0 to MPB7
  17. Click Add.

  18. If you need to change settings for an added volume, select it in the Selected External Volumes table, click Change Settings, make necessary changes, and then click OK.

  19. To add LUN paths, click Next in the Add External Volumes window. For details, see the Provisioning Guide.

  20. Click Finish when ready.

  21. In the Confirm window, review all settings, and then accept the task name or enter one.

    When you select the external volume and click LDEV Detail, the External LDEV Properties window is displayed for you to review the LDEV information.
  22. In the Confirm window, click Apply.

Preparing mapped volumes for use

After external volumes are mapped to the local storage system, you must prepare the volumes for use.

Before you begin

  • You must have the Storage Administrator (Provisioning) role.


  1. The status of the mapped volume automatically becomes Normal. If you need to initialize the data area of the mapped volume, format the volume using Virtual LUN.

  2. For each mapped volume, set an LU path from a target port to the internal volume, as shown in the following figure.

    The LU path enables host I/O to the mapped volume.GUID-BC1EB7F2-FF77-40FE-B62B-C0FF34159519-low.gif

Using mapped volumes

After external volumes are mapped and ready for use, you can perform the operations supported by Universal Volume Manager. Review supported software products and operations in Supported software for external volumes.


Access mapped external volumes only from the local storage system. Do not access them from hosts connected to the external storage systems.

In addition, do not use external storage system functions, including copy functions, to access mapped external volumes.

Recognizing the local system from the external system

Though the local and external systems are connected, the external system might not recognize the local system. You can make the external system recognize the local system by performing the Discover External Target Ports operation. If the path mapping operation does not finish after 15 minutes, though, the external system might not be able to recognize the local system. See Adding an external path to an existing path group for instructions.