I made the mistake in typing in a different Domain ID during a Nexus 1000v deployment (see post: http://terenceluk.blogspot.com/2010/11/installing-cisco-nexus-1000v-404sv13b.html) with 2 VSMs and had problems configuring the 2 VSMs in HA until I was able to change the Domain ID on the 2nd VSM to match the first one. This post serves to provide a quick answer to anyone who may run into this problem as well.
The CLI command is actually quite simple:
domain id xxx <—where xxx is your domain ID
show svs domain
You’ll be able to configure the 2 VSM as a passive node once you’ve configured it in the same domain ID value as the first one.