DP-VOL of the data direct mapping attribute
By using a DP-VOL for which the data direct mapping attribute is enabled (henceforth referred to as a DP-VOL of the data direct mapping attribute), you can create a mapping of an external volume larger than 4 TB without having to change its capacity as a DP-VOL of the local storage system.
A DP-VOL of the data direct mapping attribute is associated with the following pool-VOLs: an external volume for which the data direct mapping attribute is enabled (henceforth referred to as an external volume of the data direct mapping attribute) and a pool-VOL with System Area. For details about estimating the capacity of pool-VOLs with system area in the pool of the data direct mapping attribute, see Estimating the required capacity of pool-VOLs with System Area in the pool of the data direct mapping attribute.
If you want to use DP-VOLs of the data direct mapping attribute, you must enable the data direct mapping attribute for pool-VOLs, pools, and DP-VOLs. Follow the procedure below if you want to use a DP-VOL of the data direct mapping attribute.
Procedure
In the Add External Volumes window, add a volume of an external storage system to an external volume group.
In the Create LDEVs window, create an external volume of the data direct mapping attribute.
In the Create Pools window, create a Dynamic Provisioning pool for which the data direct mapping attribute is enabled (henceforth referred to as a pool of the data direct mapping attribute).
Specify the following volumes as pool-VOLs:
The external volume of the data direct mapping attribute
One or more normal volumes or external volumes
In the Create LDEVs window, create a DP-VOL of the data direct mapping attribute.
In the Add LUN Paths window, configure a LU path to the DP-VOL of the data direct mapping attribute.
DP-VOL of the data direct mapping attribute
The following table shows the different kinds of external volumes can be added as pool-VOLs:
|
Operation |
Data direct mapping attribute of external volumes |
|
|---|---|---|
|
Disabled |
Enabled |
|
|
Add volumes to a pool of the data direct mapping attribute |
The volumes can be added. |
The volumes can be added. |
|
Add volumes to the following pools:
|
The volumes can be added. |
The volumes cannot be added. |
The following table shows the kinds of operation that can be performed when the data direct mapping attribute of a Dynamic Provisioning pool is enabled or disabled:
|
Operation |
Data direct mapping attribute of the pool |
Remark |
|
|---|---|---|---|
|
Disabled |
Enabled |
||
|
Add an LDEV for which the data direct mapping attribute is disabled to the pool |
The operation can be performed. |
The operation can be performed. |
None |
|
Add an external volume of the data direct mapping attribute to pool |
The operation cannot be performed. |
The operation can be performed. |
None |
|
Set the depletion threshold and the warning threshold |
The operation can be performed. |
The operation cannot be performed. The depletion threshold and the warning threshold are set to 100%. |
None |
|
Set subscription |
The operation can be performed. |
The operation can be performed. |
None |
|
Protect V-VOLs when I/O fails to Blocked Pool VOL |
The operation can be performed. |
The operation can be performed. |
None |
|
Protect V-VOLs when I/O fails to Full Pool |
The operation can be performed. |
The operation can be performed. |
None |
|
Perform rebalancing |
The operation can be performed. |
The operation can be performed. However, if the data direct mapping attribute of a pool-VOL is enabled, the pool-VOL is not a target for rebalancing. |
None |
|
Define the used pool capacity |
The sum of the reserved pages capacity and the mapped capacity |
The sum of the reserved pages capacity and the mapped capacity |
None |
|
Define the licensed capacity |
The sum of the pool-VOLs |
The sum of pool-VOLs for which the data direct mapping attribute is disabled. However, the license capacity does not include the capacity of pool-VOLs for which the data direct mapping attribute is enabled. |
None |
|
Expand pool |
The operation can be performed. |
The operation can be performed. However, the capacity of pool-VOLs with System Area must be reserved in advance. For details on how to estimate the capacity of pool-VOLs with System Area. |
None |
|
Shrink pool |
The operation can be performed. |
The operation can be performed. However, if a pool-VOL for which the data direct mapping attribute is enabled is associated with a DP-VOL, you cannot shrink the pool. |
None |
|
Delete pool |
The operation can be performed. |
The operation can be performed. |
You can delete a pool only if there is no DP-VOL that is associated with the pool. |
|
Create DP-VOL |
You can only create DP-VOLs for which the data direct mapping attribute is disabled. |
You can only create DP-VOLs of the data direct mapping attribute. |
None |
|
Implement a change to Dynamic Tiering (including active flash) pool |
The operation can be performed. |
The operation cannot be performed. |
None |
The following table shows what kind of operations can be performed when the data direct mapping attribute of a DP-VOL is enabled or disabled:
|
Operation |
Data direct mapping attribute of the DP-VOL |
|
|---|---|---|
|
Disabled |
Enabled |
|
|
Configure LU paths |
The operation can be performed. |
The operation can be performed. |
|
Format LDEVs |
The operation can be performed. |
The operation can be performed. |
|
Delete LDEVs |
The operation can be performed. |
The operation can be performed. |
|
Expand V-VOLs |
The operation can be performed. |
The operation cannot be performed. |
|
Reclaim zero pages |
The operation can be performed. |
The operation cannot be performed. |
|
Execute the V-VOL full allocation function |
The operation can be performed. |
The operation cannot be performed. |
|
Protect V-VOLs when I/O fails to Blocked Pool VOL |
The operation can be performed. |
The operation can be performed. |
|
Protect V-VOLs when I/O fails to Full Pool |
The operation can be performed. |
The operation can be performed. |
|
Apply to LDEVs of SLU attribution |
The operation can be performed. |
The operation cannot be performed. |