What version of 2.1(1) are you on?
What version are you going to?
You cannot use HX Connect for the upgrade on pre-2.5 releases of HyperFlex
Use the HXDP plugin in vCenter or via SCVM CLI for upgrading
What is the upgrade state?
Check the upgrade state by logging into the SCVM (storage controller VM) with the CMIP (cluster management IP)
Run "stcli cluster upgrade-status"