Hi,
md5sum is OK to run in the shell, but will only work if the files are completely identical.
FWIW I have seen vmkfstools commands complete after loosing the ssh connection, but I only knew that because I had commands running after the vmkfstools commands which was called from within a script. So I would expect it to complete. I don't think that there's a log file you can inspect to see if it completed successfully.
--
Wil