I'm looking at setting up a new oracle install which, ideally, would access it's data over a SAN. That's not a problem, apart from the expense.
Does anyone have experience in running oracle over NFS? I'm thinking of a dedicated gigabit link betwixt client and server.
From a physical link point of view, this is gonna be pretty damned slow. The figures I hear are that gig cards have a typical throughput of 400Mbit/s, at the physical end, which, when you add in the vagaries of TCP, IP, and NFS, doesn't leave you with a whole heap of bandwidth. Someone correct me if I'm wrong about these figures.
Also, from what I've read, TCP/IP is a pretty bad medium for file transfer, as it's more optimised towards failure-recovery on poor links than raw transfer performance (Like FC).
In terms of performance, you might see ~35MB/s peak, at an educated guess, which is a joke compared to even an older (1Gb) model SAN (~100MB/s (With the right disk drives/RAID config) -- I understand you should see very close to the theoretical peak performance, given the reliability of the medium and the optimisations of the FC protocol). 35MB/s is actually less than a good high-performance IDE disk should give you nowadays.
This is not to consider latency, on which I have no data, but may well be worth considering.
Assuming that the goal you have in mind is fail-over, and cost is a big issue, I've found that simple hot-swap drives (or arrays) are the cheapest/easiest fix. With two identical machines and one array, if a machine falls over, then you just flip the cable up to another / swap the drives around. This satisfies most uptime needs, and avoids the bleeding edge cost of 'enterprise' solutions (with (semi-) automated fail over) like SANs.
In short, look elsewhere. The performance will be crap from a hardware point of view, not just a software one (Even if the gig link performs at max, 100MB/s, this is not much compared to the throughput of a good RAID array).
Cheers,
Matt
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