“Are you planning to use VMware Fault Tolerance when it’s released?”
“Probably not,” I reply.
“Why not? It looks really cool.”
“Sure, if you don’t have stable hardware or a stable hosting environment. There are probably other scenarios that I haven’t thought of where it’ll help, though.”
“What? No… it’ll be cool if you have an application crash or something.”
“Wrong. Fault Tolerance is to VMs what RAID 1 is for data. Whatever happens on disk 0 happens on disk 1. So if you delete a bunch of files they disappear from both disks, and you still need to restore from backup. You only see benefits if one of the drives dies. Fault Tolerance keeps two VMs in sync that same way.”
“Oh, so if my app crashes on one it’ll be crashed on the other one, too?”
“Yeah.”