If you are creating a new NSX-v based VI Workload Domain you will need a minimum of 120GB of disk space in the Capacity Tier for your vSAN cluster. In my lab environment I use 30GB capacity disks for the ESXi hosts, as a result I need to either use (4) hosts for the cluster or increase the size of the capacity disks.
Host sfo01w01esx01.sfo01.rainpole.local has available storage space of 30.0 GB. 2020-01-16T18:22:10.756+0000 WARN [9bef000e354c17cb,6ac5] [c.v.v.v.c.h.i.HttpConfigurationCompilerBase$ConnectionMonitorThreadBase,dm-exec-7] Shutting down the connection monitor. 2020-01-16T18:22:10.756+0000 WARN [0000000000000000,0000] [c.v.v.v.c.h.i.HttpConfigurationCompilerBase$ConnectionMonitorThreadBase,VLSI-client-connection-monitor-224] Interrupted, no more connection pool cleanups will be performed. 2020-01-16T18:22:10.756+0000 ERROR [9bef000e354c17cb,6ac5] [c.v.v.c.f.p.a.i.ValidateStorageSizeAction,dm-exec-7] 90.0 GB storage is less than the minimum required 120 GB for NSX-V based VI domain creation. 2020-01-16T18:22:10.757+0000 ERROR [9bef000e354c17cb,6ac5] [c.v.e.s.o.model.error.ErrorFactory,dm-exec-7] [2BDHG8] VSPHERE_VALIDATE_STORAGE_SIZE_FAILED Failed to validate storage size required to create a NSX-V based VI domain for the storage type VSAN.