TSDM requires connectivity to PowerProtect DD for data path purposes (see various flows in the section Transparent snapshots life cycle). This communication is facilitated using VMkernel ports on the ESXi hosts where the TSDM VIB is installed. The transparent snapshots solution would work outside of the box without dedication of VMkernel ports because any VMkernel port that can communicate with PowerProtect DD would be automatically used.
That said, for optimal predicted performance and scale, it is highly recommended to adhere to the following guidelines:
- Dedicated VMkernel Ports: Create a single dedicated VMkernel port per ESXi host. Having a dedicated VMK decreases the chances of performance degradation due to sharing of VMkernel ports with other consumers, especially vMotion and vSAN.
- VMkernel Ports Placement: We recommended placing the VMK on a VLAN that is dedicated for TSDM to PowerProtect DD traffic or a VLAN dedicated for backup traffic. It is advised that the VMK ports and the relevant PowerProtect DD ports be on the same L2 network (same broadcast domain). Avoid placing the VMKs and PowerProtect DD Ports on VLANs with heavy burst traffic such as vMotion, iSCSI networks, or FT.
- Consistent End-to-End MTU: Ensure that the MTU set on the VMkernel port and on the PowerProtect DD port is uniform from end to end. You can validate this setting using the ESXCLI command vmkping with the DF flag. For example, the following command would check that there is a uniform end-to-end jumbo frame through a specific VMK port:
vmkping -I vmk1 -d -s 8972 10.10.100.1