In the VSAN 6.0 Design & Sizing Guide, a caveat was placed around the size of a VMDK, and the Number of Failures to Tolerate (FTT) number. It reads like this: “If the VMDK size is greater than 16TB, then the maximum value for NumberOfFailuresToTolerate is 1.” I’m pleased to say that this restriction has been lifted in VSAN 6.2.