Recovering from failure if the capacity of one volume in a TrueCopy pair cannot be expanded

True Copy User Guide for VSP One Block

Version

10.4.x

Audience

anonymous

Part Number

MK-23VSP1B020-04

If the capacity of only one volume in a TC pair can be expanded while the other cannot be expanded, the resync operation in the TC pair cannot be performed after the expansion because the capacity of both volumes is not the same.

When a TC pair is used with GAD, UR, SI, or TIA, if the capacity of the P-VOL and S-VOL of one of the software products cannot be expanded, which causes an invalid state in which the expansion of the entire volume capacity is not complete. Perform the following operation to recover from the invalid state.

Verify that all of the prerequisites are met.
If the prerequisites are not met, proceed to step 4.
1. Verify that both the P-VOL and S-VOL in a TC pair meet the prerequisites for expanding the DP-VOL capacity.
  
  See the prerequisites for Expanding DP-VOL capacity used in TrueCopy pair .
2. Verify that all of the volumes meet the prerequisites for expanding the capacity in each of the software products.
  When a TC pair is used with GAD, UR, SI, or TIA, the capacity of the P-VOLs and the S-VOLs used in all of the used software products must be expanded.
When the prerequisites for expanding the DP-VOL capacity are met, retry the expansion and make sure that the capacity of the P-VOL and S-VOL in the TC pair is the same.
1. If there is not enough free space, increase the free space, and then expand the DP-VOL capacity.
2. If a TC pair is used with GAD, UR, SI, or TIA, or when a 3DC configuration is created with three UR sites, retry the expansion and make sure that the capacity of the P-VOL and S-VOL in each of the software products is the same.
- If you can expand the capacity, go to Step 3.
- If you cannot expand the capacity, go to Step 4.
Resynchronize the TC pair.
If the TC pair is used with UR, resynchronize the UR pair.

As a result, the recovery procedure from the failure is complete.
Delete the TC pair, expand the volume capacity in the SMPL status, and then re-create the TC pair.
- If you want to restore to the conditions before the expansion due to a capacity input error and others, delete the TC pair, and then recreate the LDEV with the correct capacity. After that, recreate the TC pair.
- If a TC pair is used with UR, delete all pairs, expand the volume capacity in the SMPL status, and then restore the configurations by following the procedure for creating the configurations.
  If you want to restore to the conditions before the expansion due to a capacity input error and others, delete all pairs, and then recreate the LDEV with the correct capacity. After that, restore the configurations by following the procedure for creating the configurations.
- If a TC pair is used with SI or TIA, and the capacity of the P-VOL and S-VOL in a SI pair or TIA pair is not the same, you can delete only the SI pair or TIA pair. You can read the S-VOL data in the SI pair or TIA pair before the expansion. If you want to use the data before the expansion, delete all pairs after the data reading is complete. Expand the volume capacity in the SMPL status, and then restore the configurations by following the procedure for creating the configurations.
  If you want to restore to the conditions before the expansion due to a capacity input error and others, delete all pairs, and then recreate the LDEV with the correct capacity. After that, restore the configurations.