For writes, Paxos is actually more or less optimal (in the non-failure
cases, at least). Reads are trickier, but there are ways to keep that
fast as well. FWIW, Ceph extends basic Paxos with a leasing mechanism to
keep reads fast, consistent, and distributed. It's only used for cluster
state, though, not file data.
I think the larger issue with Paxos is that I've yet to meet anyone who
wants their data replicated 3 ways (this despite newfangled 1TB+ disks not
having enough bandwidth to actualy _use_ the data they store).
Similarly, if only 1 out of 3 replicas is surviving, most people want to
be able to read their data, while Paxos demands a majority to ensure it is
correct. (This is why Paxos is typically used only for critical cluster
configuration/state, not regular data.)
sage
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