Drobo: Your Data Robot

Drobo has been around for about a year and when it first came out I judged it as "cool but not ready for primetime." Drobo is a unique RAID setup for hard drive storage. The biggest drawback was the Drobo only had a USB interface, which is not cool for video editing. Well, this summer Drobo 2 came out with Firewire 800. Data Robotics, the manufacturer, is touting read speeds of 52MB/s and writes of 34MB/s--not too shabby. They say it's good for uncompressed SD, DV, and compressed HD. They cite DVCProHD as OK, but at those data rates I'm thinking that Apple's ProRes 422 is supported too. ProRes maxes out at about 26MB/s--generally I think if the drive's speed is double the needed data rate, then you are OK.

So what makes Drobo unique? It's got a great combination of redundant data storage and the easy-to-use factor. The Drobo case holds up to 4 hard drives, and you only need 2 drives to get started. Your data is spread across the drives in such a way that if one drive failed then you wouldn't lose any data. Need more storage? This is the great part. Just slide in another hard drive of any size. Drobo incorporates you new drive into the existing RAID. If you have four drives in the case and run out of space, then no problem. Simply replace the smallest drive with a bigger drive to get more storage.

My experience with RAID has never gone beyond buying a G-Raid. Whenever I looked into setting up a RAID on my own, there were always enough drawbacks to keep me from making the plunge. It just seemed too difficult to manage all the drives. We are in drive overload anyway. Plus the added expense of more drives and SATA gear was always an issue. Granted Drobo is not cheap. At $500 without any drives, that's a hefty expense to swallow. But I think over it's life it will make up for that in the cost saved by not buying drives with cases, plus the peace-of-mind that you get with redundant storage.

There could be some drawbacks to Drobo. One is that you are putting all of your eggs in one basket. Yes, you are protecting yourself against the failure of a hard drive, but what if Drobo fails. Then you could be in real trouble and pray that Data Robotics will come to your rescue (and do so promptly). Also all of the management seems automatic. That's good if you don't want to deal with the hassle of repairing a RAID with a bad drive, but bad if the maintenance takes place in the middle of a big deadline. If a drive dies, then you don't lose any data. But then Drobo has to start shuffling around all of your data between the existing drives that are still working, and this will take a lot of time. While you are supposed to still be able to access Drobo while it does this automatic maintenance who knows what kind of performance you will get as Drobo and the drives are very busy. Will the Drobo still be able to playback and record video while it rebuilds? So while losing a drive could mean no lost data, it doesn't necessarily mean no downtime for us video editors. But overall, I'd prefer losing no data but have a slower system for a day or so, then totally losing the data.

You are also giving up some of the transportability of a G-RAID. While the Drobo can be moved, it will probably end up having all of your storage on it. If you like to put individual project on a drive, which gets moved around, then Drobo is probably too expensive for that. So it's both good and bad that Drobo can be the only drive case that you will need.

Here's an example of a Drobo system once you get the drives.
Drobo...$500
(3) 500GB Hard Drives...$325
Total Cost...$825
Total storage...930GB
That compares to my favorite type of storage a G-Raid, which gives you the same amount of storage for $355. So that's $500 up front is a lot to ask for. But I'll be thinking about his seriously in the future.

Here are some links on Drobo:
Drobo in Action
A video from Data Robotics on how Drobo works.

Drobolator
See how much storage Drobo will give you when you put different drives inside.

Drobo Firewire 800 Review
A short review of the new Drobo that gives more info on the benefits and setup of Drobo.

Daisy-Chaining Firewire Drives

I've identified some serious problems with drive performance when daisy-chaining at Link TV. Daisy-chaining is a way to hook up multiple devices (in this case, hard drives) to one port (in this case, firewire). Firewire is theoretically supposed to handle 63 devices in one chain. I've been daisy-chaining firewire drives to FCP for 6 years, but Apple doesn't consider this a supported setup for editing.

Well, I've finally run into some real problems with daisy-chaining firewire drives. I've been seeing some real poor performance out of drives. Symptoms include aborted file transfers, the hanging up of the system when a movie is played, and very slow write performance. I think I've figured out the cause. There seems to be some problems mixing certain drives in one chain. In particular, I think certain drives from Other World Computing (OWC) don't play well with other drives, in particular drives from G-Technology, like the G-Raid. OWC makes the Mercury Elite Aluminum Pro drive and RAID. G-Technology makes the G-Drive and the G-RAID.

The workaround I've identified is to make sure that a chain of drives is all from one manufacturer. For example, in our dub room setup, the G-Drive is on a firewire 400 port and the OWC drives are on the Firewire 800 port. Our computers in Edit 2 & Edit 3 have PCI cards that add 3 firewire 800 ports. So there are a lot of ports there, and it's easier to segregate OWC and G-Technology drives.

So far I've been able to diagnose this problem by checking the read/write performance of drives when I think there is a problem. I've been using the SpeedTools utility QuickBench to check drives by running the Extended Test with 20-100 MB files. If you are seeing a drive read or write at 10 MB/sec or slower then something is seriously wrong. If you think daisy-chaining may be the issue, a quick way to check is to unplug all the drives except the one that is acting up. If you then retest the drive and performance is way up, then you probably are dealing with a problem with daisy-chaining.

I've seen other, less serious problems with daisy-chaining. My write speeds on G-RAID's drops by about half when they are daisy-chained. This is a nuisance, but it's never really interfered with my work. I'm not doing any capture of 10-bit video or anything too demanding luckily.

The Trouble with G-RAID's

I often get asked for recommendations for hard drives for editing. Personally, I've probably bought 10 G-RAID's in the last couple of years and haven't lost any data yet (knock on wood.) Although, I know folks who have, and I have had some problems with these units.

One of my big concerns with G-RAID's is that they are RAID 0. As this article ("Don't get burned by RAID zero") points out RAID 0's have three potential points of failure--two hard drives, and the RAID controller. If any of these fails, you are hosed.

I also recently discovered that G-RAID's performance drops significantly, even dramatically, when used in a daisy-chain fashion (especially write speeds.)

At the moment, I'm still not satisfied with the alternatives for my lean budgets. So I'll probably buy some more G-RAID's in the future, but when people ask I can't whole-heartedly recommend them.

CalDigit S2VR Duo Review...and Firewire VR

This reviews is a big smackdown to the new G-Raid while boosting products from CalDigit. Article says that the G-Raid 2 is not up to snuff when daisy-chained--I need to check this out myself with some drives that I've got.

In the past I've said that it's much easier for me to deal with G-Raid's than SATA storage because it's easier to add storage with firewire. But if the G-Raid 2's don't daisy-chain well--then that totally changes that equation.

CalDigit S2VR Duo Review...and Firewire VR"