Should HA hardware be in separate cabinets?

view full story

http://serverfault.com – I want to host (co-located) a service at a Pier1, Q9 or some similar hosting facility. Is it best practice to put my failover hardware in separate cabinets, and in your experience, will the hosting provider allow this? My concern is that if something happens, say catches fire in the cabinet or a disgruntled rack renter pours his coke into the servers, both my HA stacks will be compromised. In your experience, if I put them in separate cabinets, can they be on the same subnet, or is it against hosting policy for me to run a cable out of one cabinet and into another? Or is it the case that (HowTos)