Mapping an external volume

Universal Volume Manager User Guide
Version
9.8.7
Audience
anonymous
Part Number
MK-98RD9016-13

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

Note the following restrictions and conditions:

  • Attributes set for the external volume before mapping, such as port security, LUN security, and 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.
Note:

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.
  • (VSP 5000 series) Numbers already assigned to another emulation group (which consists of LDEVs that are grouped every 32 LDEV numbers).
  • (VSP 5000 series) Model or serial number and LDEV ID or virtual LDEV ID of the storage system and the virtual storage machine do not match in the mainframe volume or the interim volume that you create.
  • (VSP 5000 series) To determine whether the LDEV number can be assigned, click View LDEV IDs in the Add External Volumes window when you map the external volume.
  • You must have the Storage Administrator (Provisioning) role.
  • 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.

  1. Click Storage Systems, and then expand the Storage Systems tree.
  2. Click External Storage.
  3. In the External Storage window, on the External Storage Systems tab, click Add External Volumes.
  4. In the Add External Volumes window, select an existing path group or create a new one.
    • 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.
    • To create a new external path group, select By New External Path Group, click Create External Path Group, and specify the following options.
    Option Description
    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.
    * The external target ports connected to the selected ports are searched for, and the displayed information is refreshed. If Fibre Channel connections are used for the external paths, when you use DKCMAIN microcode version 90-08-41 or later (for VSP 5000 series) or 93-06-41 or later (for VSP E series), any external target ports to which hosts are logging in are not searched for.

    To search for the WWNs of the external target ports to which hosts are logging in, perform the following:

    1. If a host is logging in to the target port of an external storage system connected to a port selected in the Discover External Target Ports window, click OK in the warning message window that is displayed.

      The Discover External WWNs widow displays the WWNs of the target ports of external storage systems to which hosts are logging in.

    2. Select the WWNs you want, and then click OK.
    Note: iSCSI names cannot be searched for.
  5. Set the priority for a path by selecting it, and then clicking Raise Priority or Lower Priority.
  6. When you have finished setting the external path groups, click OK and then click Next.
  7. In the Discovered External Volumes table, select the desired external volumes.
  8. In Initial Parity Group ID, enter an external volume group number and sequential number. When you specify an initial parity group ID that was already registered, the available IDs are assigned to the parity group IDs in ascending order from the smallest available number that is larger than the specified 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.

  9. 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.
  10. Specify Use External Storage System Configuration.
    • For VSP 5000 series: 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.
    • For VSP 5000 series: 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.
    • For VSP 5000 series: If you select Yes in Allow Simultaneous Creation of LDEVs, and select No in Use External Storage System Configuration, select any emulation type in Base Emulation Type, and then enter the number of LDEVs to be created in Number of LDEVs per External Volume.

      The maximum number of LDEVs to be created on the external volume depends on the capacity of the external volume. An LDEV on the external volume is created under the following conditions. Therefore, the number of LDEVs specified in Number of LDEVs per External Volume might not be created.

      • If an external volume exceeds the maximum capacity for the emulation type, after creating LDEVs with the maximum capacity, one LDEV with the same capacity as the remainder is created.
      • If an external volume does not exceed the maximum capacity for the emulation type, one LDEV with the same amount as the capacity is created regardless of the number specified in Number of LDEVs per External Volume.

      The following specific examples describe the relationship between the external volume capacity and Number of LDEVs per External Volume when the emulation type is OPEN-V:

      • If 1024 is specified for Number of LDEVs per External Volume when the external volume is 15 TB, three 4 TB LDEVs (12 TB) and one 3 TB LDEV are created.
      • If 2 is specified for Number of LDEVs per External Volume when the external volume is 15 TB, two 4 TB LDEVs (8 TB) are created and 7 TB remains.
      • If 2048 is specified for Number of LDEVs per External Volume when the external volume is 3 TB, one 3 TB LDEV is created.
    • For VSP E series: The maximum number of LDEVs created on the external volume differs depending on the capacity of the external volume. An LDEV in the external volume is created under the following conditions. Therefore, the number of LDEVs specified in Number of LDEVs per External Volume might not be created.
      • When the external volume is larger than 4 TB, after creating 4 TB LDEVs for the capacity, one LDEV with the same capacity as the remainder is created.
      • When the external volume is up to 4 TB, one LDEV with the same amount as the capacity is created regardless of the number specified in Number of LDEVs per External Volume.

      The following specific examples describe the relationship between the external volume capacity and Number of LDEVs per External Volume:

      • If 1024 is specified for Number of LDEVs per External Volume when the external volume is 15 TB, three 4 TB LDEVs (12 TB) and one 3 TB LDEV are created.
      • If 2 is specified for Number of LDEVs per External Volume when the external volume is 15 TB, two 4 TB LDEVs (8 TB) are created and 7 TB remains.
      • If 2048 is specified for Number of LDEVs per External Volume when the external volume is 3 TB, one 3 TB LDEV is created.
  11. 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)
  12. 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.
  13. In the expanded Options, 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.
    Option Description
    LDKC Enter 00.
    CU Enter the CU number. The default is 00. Specify a value in the following range:
    • VSP 5000 series: 00 to FE
    • VSP E590: 00 to 7F
    • VSP E790: 00 to BF
    • VSP E990, VSP E1090: 00 to FE
    DEV Enter the LDEV ID, which can be from 00 to FF. The default is 00.
    Interval Enter an interval between LDEV IDs, which can be from 0 to 255. The default is 0.
  14. (VSP 5000 series) In Initial SSID, enter the SSID, which can be from 0004 to FFFE. The default is 0004.
    You can review the current SSIDs by clicking View SSIDs.
  15. (VSP 5000 series) In Base Emulation Type, select the emulation type of the external volume.
    If you selected Yes in Allow Simultaneous Creation of LDEVs and No in Use External Storage System Configuration, you must select an emulation type. If you selected Yes in both fields, Base Emulation Type is greyed out, and OPEN-V is automatically set.
  16. 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.
    (VSP 5000 series) For details, see Capacity requirements for volumes.
  17. In Cache Partition, select the CLPR for accessing the mapped external volume.
    Note: For more information about the Cache Partition, Cache Mode, and Inflow Control settings, see External volume policy settings and functions.
  18. 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.
  19. 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.
  20. In MP unit, 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 either MPU-10 or MPU-20.

  21. Click Add.
  22. 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.
  23. To add LUN paths, click Next in the Add External Volumes window. For details, see the Provisioning Guide.
  24. Click Finish when ready.
  25. In the confirmation 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.
  26. Click Apply.
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