I have been give control of an ESX cluster. I was asked to create 2 servers which would share RDM's, i created the virtual servers and attached the RDM's to both machines making sure that the new scsi controller was physical on both nodes and that both servers could see the drives. however when i boot both servers one gets a file lock and stops booting, when i remove the RDM pointers from the afffected server it then boots normally. When i look at the cluster setting i see the VMWare DRS is not enabled, from reading the best practice doc from vmware i think this should be enabled to setup an affinity rule etc..
What i would like to know is if i turn on VMWare DRS now will it affect any of the other virtual machines listed in my ESX host of which there are about 40. i.e cause them to crash or affect other existing clusters that were setup before me.