Expanding DP-VOL capacity when a GAD pair is used with ShadowImage

Global Active Device for VSP One Block

Version

10.5.x

File Size

25537 KB

Audience

anonymous

Part Number

MK-23VSP1B011-11

ft:lastEdition

2026-06-23

You can expand the capacity of DP-VOLs used as pair volumes when a GAD pair is used with SI. This procedure provides an example for expanding the DP-VOL capacity in a configuration where the SI L1 pair and L2 pair are created for each volume of the P-VOL and S-VOL in the GAD pair. For the detailed procedures for verifying the differential data management method, expanding the capacity, and verifying the expansion during the following procedure, see Expanding DP-VOL capacity used in GAD pair.

The V-VOL to be expanded must not be an external volume.
LDEV formatting must not be in process on the V-VOL to be expanded.
The pool containing the V-VOL to be expanded must meet any of the following conditions:
- Normal condition
- The pool is not being shrunk
When using GAD, TC, or UR, make sure that there is enough software license capacity for the page capacity assigned to the expanded volume capacity before the expansion.
Ensure that the numbers of differential tables and pair tables required after the expansion do not exceed the maximum number allowed on the storage system. For information about calculating the number of tables, see Calculating the numbers of differential and pair tables for each pair.

Verify that each volume of the P-VOLs and S-VOLs in a GAD pair and SI pairs with which the GAD pair shares the same volumes meets the prerequisites.
Display detailed information about the GAD pair by using the CCI pairdisplay command..
Verify whether the current differential data management method is the SM difference management or the hierarchical difference management by a drive.
- If the SM difference management is applied, proceed to step 3.
- If the hierarchical difference management is applied, proceed to step 4.
Change the differential data management method to the hierarchical difference management.
(For VSP One Block 85) Do so for both the P-VOL and the S-VOL. If different types of storage systems are used for the P-VOL and the S-VOL, see the method of changing the differential data management method for each type in this guide.
1. Change the system settings for hierarchical difference management.
  (For VSP One Block 85) Set advanced system settings No. 5 to ON and No. 6 to OFF by using the raidcom modify user_system_opt command.
  
  Command example:
```
raidcom modify user_system_opt -opt_id 5 -opt enable
```
```
raidcom modify user_system_opt -opt_id 6 -opt disable
```
  (For VSP One Block 20 series) Set system option modes (SOMs) 1198 to ON and 1199 to OFF by using the aidcom modify system_opt command.
  
  Command example:
```
raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode enable
```
```
raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
```
2. Suspend the GAD pair.
3. Resynchronize the GAD pair.
4. Display the detailed information about the GAD pair by using the CCI pairdisplay, and then verify that the current differential data management method is hierarchical difference management.
Suspend the GAD pair and all SI pairs.
Verify the pair statuses of the SI pairs.
The SI pair volume capacity can be expanded when the SI pairs are in the PSUS or PSUE status. Verify the current pair statuses of the SI pairs.
1. If the pair statuses are not PSUS or PSUE, perform the pair operations.
2. Ensure that the pair statuses are changed to PSUS or PSUE.
Expand each volume capacity, and then verify that the expansion is complete in the expansion order shown in the following figure.

After expanding the first volume capacity (S-VOL in the GAD pair), if you cannot expand the DP-VOL capacity in the SI pair, you cannot expand the P-VOL capacity in the GAD pair, or resynchronizing the GAD pair, make sure to perform the recovery procedure described in Recovering from failure if one volume capacity in GAD pair cannot be expanded.
Resynchronize the GAD pair.

Verify that both the pair statuses of the P-VOL and S-VOL in each pair of the GAD pair have changed to PAIR(Mirror(RL)).

In addition, verify that each volume capacity in the GAD pair and SI pair is not being expanded.

The following table shows how the expansion process is displayed.

Expansion status	P column in the output of the pairdisplay command
Not being expanded	N
Being expanded	E*
* These statuses have been displayed after expanding the P-VOL or S-VOL capacity in the GAD pair and before performing the pair resync operation. After the resync operation is complete, the status is migrated to the Not being expanded status. In the SI pair, the Being expanded status is displayed for a while (30 seconds or so) after the expansion of the P-VOL and S-VOL capacity is complete. After that, the status is migrated to the Not being expanded status.

In step 2, if the differential data management method is SM difference management, change back to SM difference management using the following procedure.
(For VSP One Block 85) Do so for both the P-VOL and the S-VOL. If the P-VOL and the S-VOL are on different types of storage systems, change the differential data management method on each storage system.
1. To change back to the SM difference management method:
  (For VSP One Block 85) Set advanced system settings No. 5 to ON and No. 6 to ON by using the raidcom modify user_system_opt command.
  Command example:
```
raidcom modify user_system_opt -opt_id 5 -opt enable
```
```
raidcom modify user_system_opt -opt_id 6 -opt enable
```
  (For VSP One Block 20 series) Set SOMs 1198 to OFF and 1199 to ON by using the raidcom modify system_opt command.
  Command example:
```
raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
```
```
raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode enable
```
2. Suspend the GAD pair.
3. Resynchronize the GAD pair.
4. Display the detailed information about the GAD pair by using the CCI pairdisplay command, and verify that the current differential data management method is SM difference management.
5. (For VSP One Block 85) If the settings of advanced system settings No. 5 and No. 6 have been changed, set No. 5 to OFF and No. 6 to OFF by using the raidcom modify user_system_opt command.
  Command example:
```
raidcom modify user_system_opt -opt_id 5 -opt disable
```
```
raidcom modify user_system_opt -opt_id 6 -opt disable
```
  (For VSP One Block 20 series) If the settings of SOMs 1198 and 1199 have been changed, set SOMs 1198 to OFF and 1199 to OFF by using the raidcom modify system_opt command.
  Command example:
```
raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
```
```
raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
```