Jun 21, 2010

Build a Fast and Inexpensive RAID array

Build a Fast & Inexpensive RAID array

Whether you're a new or experienced editor one thing of concern to all is both storage of clips and fast access either for grabbing files and especially for editing. Fast access always means an array of some sort, be it e-SATA, SCSI or fiber. But arrays regardless of which kind usually mean spending thousands of dollars both in array hardware and HDD's themselves. This is an alternative to the ultra-expensive arrays - and it works, very well (test result enclosed).

This setup comes with some very important caveats, so pay attention before you spend your money or ask tons of questions:

- This is an e-SATA array, meaning there is no on-board controller cache and the only cache available is what the HDD's themselves have. That translates into the fact that the array will start out very fast however, as it gets continually used throughout an edit or if multiple file transfers occur it will slow down, sometimes to half it's original speed depending on use. Speed is regained when the individual drive cache is flushed (usually during system reboot or over time if the drives are not used for about 10 minutes or so). Until there are e-SATA HBA's that have on-board cache there is no way around this performance characteristic.

- If you have never setup an array or don't understand how they work, don't start spending your money on this setup UNTIL you get some research done or training by someone who can walk you through setup and usage.

- This setup, while very cost-effective and inexpensive, is more complex in that it uses multiple enclosures each with it's own power supply. That means there are multiple points of failure since you're dealing with more than one independent power supply.

- This setup does not allow for "hot-swap" as the drives are in a fixed enclosure - more on that as the hardware is discussed. Here's the physical setup:

(1) Highpoint Technologies "RocketRAID" 2322 PCI-e HBA w/ (2) mini-SAS to e-SATA cables. (that's a total of 8 individual drive cables) $295 - Cables are separate at $45 each depending on where you get them. $385 total

(4) OWC Mercury Elite-AL Dual Bay SATA Enclosures (2 drives per enclosure, direct JBOD connection) $75 each / $300 total

That's an 8-drive e-SATA array for less than $800 (not including HDD's)!

How fast is it? Using the KONA System Test I ran it using the same codec I shoot in DVCPRO-HD 720p and got just under 280 mb/s READ with a 1gb file test. That's damned impressive for an array that was thousands less than a SCSI setup. This test was done with (8) WD5000YS drives in a RAID-0 configuration. AMUG and BARE-FEATS tested this card with faster numbers but they used a Mac TERMINAL application to do the test, I prefer to use the KONA test because it's specific to mimicking a video-edit environment, so I feel the numbers are more real-world and not hype.

The RocketRAID 2322 is the first e-SATA HBA to create the array in HARDWARE not software, so there's no OS overhead being used for the array management. It's also the first HBA to allow for 8-drive access externally and, (2) RR2322's can be connected in parallel for a total of 16 drives! (this functionality in MacOS requires Disk Utility to join them, in XP you just add a jumper cable and the cards do the work). The card will do RAID 0, 1, 5, 10, and parity on 5, 10.

The OWC enclosures are unique; they do not have HOT-SWAP trays, the drives are fixed so you lose the ability to quickly replace a drive. They also have their own individual power supply, so that means cabling becomes a bit of a mess in this tested config: (8) e-SATA data cables and (4) power cables between (4) enclosures.

The OWC "black boxes" are whisper quiet; with all 4 running I barely heard the fans in the back.

This is not an ideal setup for everybody as it is geared to those who want or need a fast array for accessing OR storing their media files but don't have mega-bucks for a SCSI or fiber array. Here's a cost comparison (minus the cost of HDD's, HBA and cables)

(4) OWC "Black boxes" as described above: $300
(2) Sonnet Fusion 400 enclosures (8 drives total, hot-swap capable, e-SATA connection): $760
(2) Wiebetech SilverSATA IV (same as above): $900
(1) Enhance-Tech T8 SCSI 8-drive enclosure (SATA to SCSI backplane): $2200
(2) Fibrenetix Qubex Fibre 6-drives x2 enclosures (SATA to Fibre backplane): $8100

As you can see, as you go up the food-chain of faster connectivity the costs skyrocket, sharply. Add the cost of HDD's and the HBA and you'll see how cost-effective this e-SATA suggested setup is.

It should be noted however, that no e-SATA array regardless of enclosure or connection type is as fast nor as data-stable (constant data-frame-speed) as SCSI or fiber. But, for the added speed and stability you really have to cough up some serious buckage - something most indies just can't afford or justify.

NOTE:  Highpoint has newer cards that will provide the same functionality as the 2322 but with more features.

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