so, i proceeded to set up another iscsi device on that nas, got it mounted right with all the correct data. neat.
my vmware esx server still reported that its images were "Unknown Host" of course. but blast it, what were the names of these systems before? my vsphere console server was down. crud.
easy, i went here:
and there they were.
all i needed to do to reassociate them was to change the /vmfs/volume/path to the correct one. i rebooted the vmware esx server and all was cool.