This help page provides information to guide you through the procedure to create a Logical Unit. It contains the following topics:
Logical units are user-designated partitions of the free storage space in an array and are used by a host to manage the data in the storage space they define. A logical unit can include all of the free storage space on an array or only part of it. For example, you could create a logical unit for the free space on each drive, or you could divide the free space on a drive into parts and create a logical unit for each part. The parts can be any size you want. You could also create a logical unit that includes part of the free space on each of the drives.
The number of logical units you can create depend on your system. Refer to the user's guides for your system's specifications.
Each logical unit is assigned a number to identify it. The numbers can be from 0 to 1023 and are called Logical Unit Numbers, or LUNs. Since the LUNs are the usual way to refer to the logical units, the acronym LUN is often used instead of logical unit.
There are several types of LUNs that can be created and used on the array.
Standard logical units or LUNs, which are just designated partitions of storage space. They are also called volumes.
Differential Management Logical Units, or DMLUs. DMLUs are logical units that consistently maintain the differences between them.
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NOTE: DMLUs are pre-configured and are not user-accessible on the Simple Modular Storage 100 array. Modifying or using the pre-configured DMLU for any purpose other than which it is intended will void the warranty and any support agreement with Hitachi Data Systems. |
SnapShot Logical Units are virtual volumes and are specified as the secondary volume of a SnapShot pair when you create a pair. See Create SnapShot Logical Unit for more information.
Hitachi Data Systems storage arrays are set up at the factory with one or more logical units, depending on the model. This helps users by making the arrays easier and faster to configure. The factory configurations are described below, by model.
The Simple Modular Storage 100 array is set up at the factory with either two or three preconfigured LUNs, depending on the number of controllers in the array. The following table lists the parameters of the preconfigured logical units.
|
Number of Controllers |
Number of LUNs |
LUN Numbers |
LUN |
Size |
Port Assigned |
Purpose |
|
1 |
2 |
LUN 0
LUN 1023 |
LUN
DMLU |
50 GB
10 GB |
0A
none |
Normal use. Can be allocated to a host. May be spread
across multiple drives. |
|
2 |
3 |
LUN 0 |
LUN |
50 GB |
0A |
Normal use. See above. |
The AMS 2000 Family of arrays are set up at the factory with one pre-configured LUN. The following table lists the parameters of that LUN.
|
Number of Controllers |
Number of LUNs |
LUN Members |
LUN Type |
Size |
Port Assigned |
Purpose |
|
2 |
1 |
LUN 0 |
LUN |
50 GB |
0A |
Normal use. Can be allocated to a host. May be spread across multiple drives. |
To create a logical unit:
Click Create LU from the Logical Unit tab of RAID Groups window or the Property of RAID group . The Create Logical Unit dialog is displayed.
Select the Basic tab.
Enter the appropriate information in the following fields. See the on-screen instruction.
RAID Group
LUN
Capacity
Click the Advanced tab to set advanced options. If you do not need advanced settings, continue to step 8.
Set the stripe size. This is a size to write separated data to drive.
Select to do format of created logical unit. By default, to do format is sat.
Select the free space you want to create for the logical unit and set manually or set automatically. To set manually, check the box on free space table. Input the first LUN, when more than 2 free space is used this LUN is set. Select set automatically, set LUN in descending order from the maximum available LUN.
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NOTE: In some selected arrays, you cannot set automatically or manually and have only free space available to select. |
Click OK. The results window is displayed.
Click Close to finish. Confirm your changes in the Logical Unit window.
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Button |
Description |
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Create More LU |
Creates additional LUs with the same parameters. |
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Add to iSCSI Target |
Creates a logical unit assign to existing iSCSI target. Select to assign to iSCSI port and iSCSI target. |
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Create iSCSI Target |
Creates a logical unit assigned to new iSCSI target. |
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Add to Host Group |
Creates a logical unit assigned to an existing host group. Select to assign fibre channel port and host group. |
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Create Host Group |
Creates a logical unit assigned to new host group. |
See Also (back to top)
The following topics within this online help provide information that may be helpful in understanding the information on this page, and/or may provide additional information that is related, but not required to understand this topic.
Create
and Map Volumes
