I'm looking to deploy an application based on Oracle DB, and I was assuming that it would be possible to easily do active/passive clustering (with RH Cluster or Heartbeat) and synchronous replication a la drbd, but all the hosting providers I'm talking to are looking at me funny. Some have offered ghetto replication they called "log shipping," whereby files are asynchronously sync'd over the network, but that means that we may potentially lose up to an hour of data.
The alternative is to pay millions of dollars (well, tens to hundred of thousands) for Oracle Data Guard or somesuch.
I'm puzzled because I've worked for years on a very demanding system (tens to hundreds of GB of payment transactions) that did what I'm asking for close to $0, using PostgreSQL over DRBD over a Metropolitan Area Network.
I'm assuming here that SAN replication does the same thing as DRBD, i.e. synchronous replication where written blocks are ACK'd only after they've been written remotely. Am I wrong?
Am I missing something here?