Hi André,
the mpx.vmhba32:C0:T0:L0:3 is the SD card where I boot ESXi from. Complete different drive in that case.
As I already had the old ESXi 6.0.0 on the boot partition of the RAID disk (I've changed to an independent boot medium (SD) this summer and also did the upgrade to ESXi 6.5), I've booted to the old 6.0 this morning. In that case only the "naa" drive (RAID) is there, but the vmkfstools --growfs fails with the same error message.
Current version is ESXi 6.5.0 U2 Build 10719125.
Marco