Data paths must be designed to adequately manage all possible amounts of data generated by the host and sent to the P-VOL and S-VOL.
Sufficient bandwidth must be present to handle data transfer of all workload levels. The amount of bandwidth required for your TrueCopy configuration is based on the amount of I/O sent from the host to the primary storage system. You can determine required bandwidth by measuring write workload. Workload data is collected using performance monitoring software. Contact customer support for more information.
| Data path interface connecting primary and secondary storage systems | Model | Supported firmware version |
|---|---|---|
| 32-Gbps FC 1 | VSP One B20 series and VSP One B85 | VSP One B20 series: All versionsVSP One B85 A0-05-41-xx or later |
| 64-Gbps FC1 | VSP One B20 series: All versionsVSP One B85: Not supported | |
| 10-Gbps iSCSI | VSP One B20 series: All versionsVSP One B85: Not supported | |
| 25-Gbps Ethernet2 | A3-04-21-xx and later | |
| 32-Gbps NVMe-oF | Not supported | |
| 64-Gbps NVMe-oF | Not supported | |
| 100-Gbps NVMe/TCP | Not supported |
- VSP One B85 32Gb Fibre Channel Board V2 and 64Gb Fibre Channel Board V2 are not supported.
- VSP One B85 You can install 10GBASE-T SFP modules on the 25-Gbps Ethernet channel board. If you do, the transfer speed is 10 Gbps.
You cannot create a pair combining an NVMe-oF volume (volume that is defined as a namespace on the NVM subsystem added with an NVM subsystem port) and a Fibre Channel volume or iSCSI volume (volume set with an LU path). See the following table.
| Primary data path | Secondary data path | Supported |
|---|---|---|
| NVMe-oF or NVMe/TCP | NVMe-oF or NVMe/TCP | Yes |
| NVMe-oF or NVMe/TCP | Fibre Channel or iSCSI | No |
| Fibre Channel or iSCSI | NVMe-oF or NVMe/TCP | No |
| Fibre Channel or iSCSI | Fibre Channel or iSCSI | Yes |
- Create at least two independent data paths (one per cluster) between the primary and secondary systems for hardware redundancy for this critical element.
- When creating more than 4,000 pairs, restrict the number of pairs so that a maximum of 4,000 pairs use one physical path to distribute the loads on the physical paths.
- In a disaster recovery scenario, the same write-workload will be used in the reverse direction. Therefore, when planning TrueCopy for disaster recovery, configure the same number of secondary-to-primary data paths as primary-to-secondary copy paths to maintain normal operations during disaster recovery. Reverse-direction paths must be set up independently of the primary-to-secondary paths.
- When you set up secondary-to-primary data paths, specify the same combination of CUs or CU Free and the same path group ID as specified for the primary-to-secondary paths.