Fibre Channel Storage?

Dave Robertson asks: "Fibre channel storage has been filtering down from the rarefied heights of big business and is now beginning to be a sensible option for smaller enterprises and institutions. An illuminating example of this is Apple's Xserve Raid which has set a new low price point for this type of storage - with some compromises, naturally. Fibre channel switches and host bus adapters have also fallen in price but generally, storage arrays such as those from Infortrend or EMC are still aimed at the medium to high-end enterprise market and are priced accordingly. These units are expensive in part because they aim to have very high availability and are therefore well-engineered and provide dual redundant everything." This brings us to the question: Is it possible to build your own Fibre Channnel storage array? "In some alternative markets - education for example - I see a need for server storage systems with very high transaction rates (I/Os per second) and the flexibility of FC, but without the need for very high availability and without the ability to pay enterprise prices. The Xserve Raid comes close to meeting the need but its major design compromise is to use ATA drives, thus losing the high I/O rate of FC drives.

I'm considering building my own experimental fibre channel storage unit. Disks are available from Seagate, and SCA to FC T-card adapters are also available. A hardware raid controller would also be nice.

Before launching into the project, I'd like to cast the net out and solicit the experiences and advice of anyone who has tried this. It should be relatively easy to create a single-drive unit similar to the Apcon TestDrive or a JBOD, but a RAID array may be more difficult. The design goals are to achieve a high I/O rate (we'll use postmark to measure this) in a fibre channel environment at the lowest possible price. We're prepared to compromise on availability and 'enterprise management features'. We'd like to use off the shelf components as far as possible.

Seagate has a good fibre channel primer, if you need to refresh your memory."

Comments

why "build" your own array?

[heliocentric]

Sun's A5200s are cheap on eBay, and you can pick up something like a 420r or a 250 to drive the thing. Put a qfe card in with the free sun trunking now for Solaris 10 and it'll serve up your files super speedy, all for very reasonable.

My friend, recursive green, has three A5200s in his basement right now, one stores his *ahem* photo collection and is web accessible.

I think new(er) fibre things are getting cheaper, but what was often high-end data-center-only big-$$ of a few years ago hits the price point of "at home" now.

Re:why "build" your own array?

[LordMyren]

You're right and you're wrong. I myself started with T-cards and 36gig cheetahs. It was amazing after a life of cheap low performant IDE (college student at the time). But shit kept breaking, the hacks kept getting worse and worse, the duct tape bill started getting too big and I just got tired of it. Drives would go offline and there was no hotswap support... kiss your uptime goodbye.

So I exactly that, went on ebay and bought a pair of photons. Only 5100's, but 28 drives was pretty nice.

I was pretty undewhelmed. They were a steal when I got them (well, a "good" price when you factor shipping), but the performance was never there even with really good 10k6 cheetah's. RAID never helped, no matter how it was configured. It just didnt seem that useful.

Plus the A5200's weigh 125lbs and hauling them between dorm rooms proved less than fun.

And even locked my basement closet I could hear the roar of two A5100's. I'd been "meaning" to get rid of them for a while, but now that I'm changing states... it was finally time. I sold em on craigslist for $280 for both. Same I bought em for, and taht includes shipping.

I dunno, If I were anyone with a brain, I'd wait another year for SAS go to ape-shit on everyone. The enclosure-hostcontroller system is a smart breakdown that'll really help beat away the single-vendor-solution... the reason everyone can charge so much for hw now is that everything is one unit, the enclosures, the controller, its a big package with a nice margin. when XYZ company can come along and sell you a 24 drive enclosure for pennies that you can plug in to a retail SAS controller... its a game changer. Just watch the rediculous margins drop.

If you need something now, just get SATA raid. Intel's new IO processor is amazing, it'll give you really nice performance. But otherwise, I'd say wait for SAS. I suppose its still more expensive than a pair of A5100's, but I'd wager the performance will be better.

As a side note, I sometimes wonder whether the fibre cabling i bought was bad. I really couldnt sustain more than 40 MB/s even doing XFS linear copies, even with 14 drives dedicated to the task. I'm not sure if bad cabling would've given me some kind of overt error, or might have just quietly degraded my performance.

Myren