We’ve been working on migration strategies and TCO numbers for the new SAN purchase.

I’ve also generated some base TCO numbers that I can build a more complete model from. Those TCO numbers are based on some theoretical growth numbers. It’s interesting to see how each vendor’s options stack up.

The technical team has spent more time with the vendors discussing solutions. We’ve tentatively decided that we like Fiber Channel, at least for the new Db Tier machines. I’m waiting for quotes from the vendors so I know how that affects the costs. 

So why do we like FC?

• We can’t get the throughput with iSCSI that we want, at least at a sane, and same, physical connection count.
• We’ll have a ton of extra cables in the rack, leading to reduced air flow and additional management overhead, more switch ports, etc.
• If we go to denser servers, which we’re looking at, we’ll want even more ports, or 10Gbe.
• Power on 10Gbe is something like 33w per port. I’m still waiting to see what the per port power on 4 Gb/s FC is like.
• 10Gbe copper switches won’t be out for a few months yet. And, even though I trust Extreme Networks a LOT, I’m not sure I want a generation 1 product at the core of the network.
• 10Gbe will also cost a lot.
• We can run fiber longer, with less delay.
• FC is apparently more mature than iSCSI.

FC Downside?

• It costs a bunch more.
• We have a minimal set of FC skills in house, at least when compared to IP, SCSI & Ethernet.
• Additional switching equipment.
• Additional management overhead of those switches.

We’re still determining if we need it everywhere. I think we need it in the Db Tier though.

-Edward Muller