You must have Storage Administrator (Remote Copy) role to perform TrueCopy operations.
Basic TrueCopy operations consist of the following operations.
- Check prerequisites for each procedure.
- Always check pair status. Each TrueCopy operation requires the pair to be in a specific status.
- Create a pair, in which the S-VOL becomes a duplicate of the P-VOL.
- Split a pair, which separates the P-VOL and S-VOL and allows read/write access to the S-VOL if desired.
- Resynchronize a pair, in which the S-VOL again mirrors the on-going, current data in the P-VOL.
- Delete a pair.
Disaster recovery procedures are discussed in Disaster recovery.
Note:
- When a host and the storage system are connected using Fibre Channel or iSCSI, set an LU path to the volume that is subject to pair operations or for which the pair status is to be checked. If the LU path setting is canceled for a volume, pair operations or pair status checking cannot be performed for the volume.
- When a host and the storage system are connected using NVMe-oF, set the volume that is subject to pair operations or for which the pair status is to be checked as a namespace, so that the host can recognize the volume. You cannot perform pair operations or check the pair status for a volume if the volume is not set as a namespace on the NVM subsystem to which NVM subsystem ports have been added.
- Pair operations cannot be performed when changing the firmware, nor if firmware changes are cancelled. If you start a firmware change, make sure it is complete before performing pair operations. You can perform pair operations from CCI even while changing the firmware or when firmware changes are canceled.
- When any of the following conditions occur during
TC pair duplication, sometimes the
TC pair splits to prioritize refresh I/O rather than
TC pair duplication.
- The MP unit processor operation rate which the P-VOL belongs is 70% or higher in the primary system.
- Refresh I/O inflow for the P-VOL is large in the primary system.
- MP unit write-pending which S-VOL belongs is 65% or higher in the secondary system.
When creating or resynchronizing TC pairs, be aware of the load of the storage systems at each site.
- When you use a volume connected to a host by using NVMe-oF, you can use only CCI to create a TC pair. For details about pair operations using CCI, see the relevant topic in the Command Control Interface User and Reference Guide. Note that you can use both HDvM - SN and CCI for operations other than creating pairs (for example, splitting, resynchronizing, or deleting pairs).