Just for reference; we had a problem this morning with a couple of VMs. The infrastructure had to be shutdown over the weekend as the power was turned off so that they could work in safety installing a new power feed.
The SAN was started first along with switches; the hosts started several minutes later. The VMs were set to start up automatically. However, there was a problem with a couple of these and several entries in the event viewer "iSCSI Login error 0x490". Having checked the error I was lead to a kb article that indicated the error lay in the connectivity; the suggestion was that a port needed to be checked in the SQL Configuration Manager. I checked the settings and they seemed to be OK.
However, the problem & solution was much more simple; one of the drives containing the SQL components was marked as "offline". Once it was set to "Online" again, the SQL server started up and the error message vanished.
I highlight this because it is the second time we have had an issue with a drive going offline (it was SQL server last time as well). It might be worth keeping this in mind; it could save you a lot of heartache.