When logged into spa or spb, If you see a host (VM1) "host agent unreachable. This means that mostlikely the naviagent on the host needs to be manually started. To do this follow these steps. >Log in using putty to the vm host >/etc/init.d/naviagent stop >/etc/init.d/naviagent start

You should get a ok message.

Then Log back in to one of the storage processors and right click on the host in question (VM1) and choose update now. The message host agent unreachable should go away.