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