When you create an LDEV at the same time that you map an external volume, you cannot select the following LDEV numbers: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 the Universal Volume Manager User Guide.
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.
Procedure
Open the External Storage window.
In Command Suite:
On the Resources tab, click Storage Systems, and then expand All Storage Systems.
Expand the target storage systems, right-click External Storage, and then select System GUI.
In Device Manager - Storage Navigator:
Click Storage Systems, and then expand the Storage Systems tree.
Click External Storage.
On the External Storage Systems tab, click Add External Volumes.
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. You can specify a value in the following range:
- VSP G200: 0 to 2,047
- VSP F400, F600: 0 to 4,095
- VSP G800: 0 to 14,079
External Paths: If the port or WWN 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.
Click Next.
In the Discovered External Volumes table, select the desired external volumes.
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 Virtual Storage Platform G200, G400, G600, G800 Provisioning Guide .
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.
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.
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)
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.
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. You can specify a value in the following range:
- VSP G200: 00 to 07
- VSP F400, F600: 00 to 0F
- VSP G800: 00 to 3F
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.
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.
In Cache Partition, select the CLPR for accessing the mapped external volume.
For more information about the Cache Partition, Cache Mode, and Inflow Control settings, see External volume policy settings and functions.
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.
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.
In MP Unit ID, select the MP unit for the external volume. MP unit assignment should evenly distribute work across the available processors.
The selectable values are MPU-10, MPU-11, MPU-20, or MPU-21. The value depends on the configuration of the device.
Select Auto (the default) to cause an MP unit to be automatically assigned by the system. If Auto cannot be selected, the MP unit with the lowest number is selected by default.
Click Add.
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.
To add LUN paths, click Next in the Add External Volumes window. For details, see the Virtual Storage Platform G200, G400, G600, G800 Provisioning Guide .
Click Finish when ready.
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.
In the Confirm window, click Apply.
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