Many times when using my lab after a bit of inactivity I come back to a round of having to reset the root password on various VMware appliances including vRSLCM using the procedure in VMware KB 52431. Thankfully there is a way to change the vRSLCM root password expiration to a slightly longer time frame by running the following command from within the appliance command line:

chage -I -1 -m 0 -M 99999 -E -1 root

The 99999 in the above command is the password expiry in number of days and is set to the max allowed. In a production environment you would want to set this to something more reasonable.