Sunday, May 31, 2009

Work In Progress-- RAID Expansion Chasis

The June issue of DV Magazine will feature my article on 3 RAIDS in a range of price and features. I'll be looking at a 2-drive unit from CalDigit, an 8-drive RAID 5 from Sonnet Technology and finally a Fibre-Channel server-level device from Dulce Systems.

Due to space limitations in print, I noted that I'll also be reviewing for the web an extension of an 8-drive array using SAS-Expander chassis and controller technology.

He is the testing so far.

For this test, I'm using another HighPoint RocketRaid 4322 cards, referenced in my Ultimate Raid article here on the blog as well as in DV. The HighPoint 4322 is my choice of RAID controller cards. It's dedicated Intel processor is faster than the prior generation; it is expandable with a battery backup daughter card; it supports both eSata and SAS drives through miniSAS 4-channel connectors; it is expansion chassis ready. My tests have already shown that the 4322 is faster than the 3xxx series. And at a price of $599, there is simply nothing on the market that comes close to its price/performance benefits.

I'm testing a 16-drive chassis from AIC, the XJ1100, which retails around $1600. It is a sturdy chassis with pop-out swappable drive trays requiring screws to secure the drive to the tray. Unlike many enclosures I've seen or tested, the drives trays are not lockable.

The unit is effectively 2 8-drive devices connected internally by an expansion circuitry. 4 miniSAS connectors on the rear allow dual connections to the controller card and dual connections to other 16 drive expansion chassis. Chaining multiple enclosures together can create some significant storage with blazing speed!

Like any enclosure of this class the XJ100 contains heavy-duty fans. Heat is, after all, a hard drive's greatest enemy. If you are using this enclosure for editing, you will definitely want to locate it in another room or within a soundproof enclosure. It sounds like a windtunnel. In justfication, however, all large enclosures such as this are noisy as they really are designed to be servers.

I'm testing this enclosure with 400gb Seagate Cheetah 15K SAS drives and Seagate 1tb ES-class eSata drives.

This is a preliminary report on testing the Seagate drives.

The Seagate Cheetah drives came pre-initialized as a RAID 6 and formatted to a little over 6 tb.

Note that 15K SAS drives are not available in the capacities of eSata drives, but the advantages are significant. The SAS drives are built for 24/7 heavy use with 1.6 million hours MTBF. Seagate designs them with specific error-checking algorithms. They are dual-ported, allowing the next drive in the array to take over immediately in the event of failure. For purposes of video, and this would apply specifically if the drives were being used in a SAN configuration, latency is a mere 2ms as opposed to a 4.1ms latency of eSata drives.

Because of this low latency and immediate response, EditShare only uses SAS drives in their turnkey SAN systems. I am certain this is the case for other vendors as well.

A faster rotational speed will naturally pump data faster and more reliably.

Take a look at the AJA System Test results for the Cheetah drives. Note as well that this speed is not just a function of the drives; the RocketRaid 4322 contributes significantly.

All I can say about results like that is WOW!

To test this in the real world, I copied to the drive several Red R3D files and exported 2K Quicktime files. I brought these into FCP which transcodes the files to ProRes 422 HQ. These 23.98 fps clips played without a single glitch. I also transcoded to Blackmagic 2K 2048x1556 4:4:4 RGB. All footage played without a hitch. Now something else-- I was able to play these files in FCP with scopes open and updating in real time. Even on my 8-drive array, I will sometimes drop frames while playing back live scopes (seems to be a common FCP problem). I always suspected the culprint was drive speed and this array helped prove my point.

As I write this entry, I'm now initializing a raid using the 16 Seagate ES drives. I'll report on those in the next installment and then the whole article will reprint on DV.COM once my June article appears.

Who is the logical customer for this technology?

For the RocketRaid card, the answer is any of us wishing to create the fastest raid with parity that relatively little money can buy.

The XJ1100 is definitely an enclosure for someone who stores massive amounts of data and needs the luxuries of speed, capacity, and redundancy. As one documentary filmmaker friend who dropped by the studio as I was testing the unit said, "I'd fill this in a year."

The Seagate 15K Cheetah drives are suitable for high end work. Their speed and dependability makes them candidates for SAN applications, whether in this enclosure or in another system. Any user loking for the top performance in any hard drive regardless of the system, should strongly consider the Cheetah drives. Keep in mind that the 400gb 15K Cheetahs run in the $525 range. But speed and data security... priceless.

Stay tuned for results with the Seagate ES (Enterprise Series) eSata drives.