The supported operations might differ depending on the status of the pool to which the target Dynamic Provisioning virtual volume belongs. For example, Volume Migration might not be executed in certain conditions.
The following table shows whether Volume Migration operations are available for each combination of source and target volumes.
|
Source Volume |
Target Volume |
|||||
|---|---|---|---|---|---|---|
|
External Volume |
DP-VOL in Normal state |
DP-VOL in Blocked state | DP-VOL for which the pool is full | |||
|
Normal |
Data size will exceed the threshold of the pool after migration | Pool will be full after migration | ||||
|
External Volume |
Available |
Available |
Available |
Not available |
Not available |
Not available |
|
DP-VOL in Normal state |
Available |
|||||
|
DP-VOL in Blocked state |
Not available |
Not available |
Not available |
|||
|
DP-VOL for which the pool is full |
Available |
Available |
Available |
|||
The following table shows whether Volume Migration operations are available for each status of Capacity Expansion.
| Source Volume | Target Volume | Volume Migration Behavior | |||
|---|---|---|---|---|---|
| Volume | Capacity Expansion | Volume | Capacity Expansion | Volume Migration | Canceling Volume Migration |
|
DP-VOL |
Capacity is expanding |
DP-VOL |
Capacity is expanding |
Not available* |
Not available |
|
Capacity has expanded, or capacity is not expanded. |
Not available* |
Not available |
|||
|
External volume |
None |
Not available* |
Not available |
||
|
Capacity has expanded, or capacity is not expanded. |
DP-VOL |
Capacity is expanding |
Not available* |
Not available |
|
|
Capacity has expanded, or capacity is not expanded. |
Available |
Available |
|||
|
External volume |
None |
Available |
Available |
||
|
External volume |
None |
DP-VOL |
Capacity is expanding |
Not available* |
Not available |
|
Capacity has expanded, or capacity is not expanded. |
Available |
Available |
|||
|
External volume |
None |
Available |
Available |
||
|
*Confirm that capacity expansion is complete, and then migrate the volume again by specifying a volume whose capacity is the same as the one for the volume after expansion. |
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- If you create a Volume Migration pair by using a Dynamic Provisioning virtual volume whose capacity is larger than 4,194,304MB (8,589,934,592 block), the differential data is managed in the pool to which the Volume Migration source and target volumes are associated. In this case, a maximum of four pages are required as the pool capacity for data managing differences, for each unit (4,123,168,604,160 bytes) of the volume.
- If you create the Volume Migration pair during the processing of reclaiming the zero data (including reclaiming the zero data by the WriteSame/Unmap command or rebalancing), the processing of reclaiming the zero data will be suspended.
- If reclaiming zero pages is in progress on a source or target volume during Volume Migration pair creation, the pair might not be created. Therefore, to create a pair, avoid the time period when reclaiming zero pages is in progress.
- If the WriteSame/Unmap command is issued for the source volume or target volume of the Volume Migration pair, the processing of reclaiming the zero data, by the WriteSame/Unmap command, will not be performed.
- Even if rebalancing operates, the processing of reclaiming the zero data by rebalancing will not be performed for the source or target volume of the Volume Migration pair.
- If you create the Volume Migration pair during the processing of the Unmap command issued when the system option mode 905 is on, the pair creation may fail. If this occur, retry the pair creation after a while. If the problem persists despite retrying, turn off the system option mode 905, and then retry the pair creation.
- When you use an external volume as the source volume, and use the Dynamic Provisioning virtual volume (DP-VOL) as the target volume, pages are allocated to the entire area of the DP-VOL (target volume).
- When you use the DP-VOL as the target volume and the pool to which the target volume belongs is full, the migration of the volume by the Volume Migration fails. Confirm that the pool to which the target volume belongs has sufficient free space and then migrate the volume.