Configuring vSAN VMkernel port to support Jumbo Frames.
Resolution
1) Change the MTU value to 9000 on the physical switch port the vSAN vmnic is connected to. Note: Some switches require a size larger than 9000 to handle packet overhead. Check with the network admin or Switch Documentation to be sure.
2) Configure the MTU value of vDS switch (if applicable) so that all port groups and ports use Jumbo Frames or vSS. Enable Jumbo Frames for Networking
vDS
vSS
3) Change the VMkernel port to 9000.
4) When all hosts have been configured, test connectivity on all hosts between the vSAN VMkernel interfaces.
Best Practice: These steps can cause a brief connection interruption. Therefore, a maintenance window should be scheduled which would allow for all VMs to be powered off while the changes are being made. Once Jumbo Frame connectivity is confirmed between all hosts, VMs can be powered on again.