A Storage Primer
Often times, additional hard drives are added to provide more storage.
Over time, binders with sleeves for CD and DVD storage can take up a lot of space.
If the media department of your congregation is shooting video and recording it—or even thinking of recording it—no doubt you’ve considered storage options that go beyond the internal hard drives of your workstations and laptops. After all, video is the most gigabyte-hungry form of data you’re likely to collect.
Consider broadcast-quality, standard-definition video: a minute of uncompressed NTSC video (or certain types of compressed high-def video) is equivalent to, very roughly, 1GB—so 60GB per hour. Let’s say you’re recording three one-hour services a week with two cameras, and you want to keep the footage of a month’s worth of services online and at your editor’s fingertips. That’s a minimum of 12 hours, so 60GB per hour x 12 hours x two cameras = 1,440GB. That’s well over a terabyte. Even recording MiniDV at a much lower 25Mbps bit rate, you’re basically filling a 250GB hard drive every month. The case for an organized approach to external storage becomes clear as the tapes are piling up in your office, and suddenly your pastor wants a new promotional video within a week.
Of course, storage capacity is not the only thing to consider. Your video assets are extremely valuable, and so is your time. At this point, if your media department is like that of many churches, chances are good that you take an a la carte approach to storage. That is, when one 250GB LaCie or Maxtor drive fills up, you buy a new one and stash the old one in a closet.
This presents at least two potential problems. First, when you need a shot from the Easter production from two years ago, good luck finding it within a reasonable time frame. Once you do find the shot, the slow transfer rates of standard FireWire drives present another time-trap. Second, external hard drives with moving parts are more sensitive than many people realize. Though they’re often treated like sturdy bricks to be tossed and stacked, they can easily malfunction, putting your non-recoverable media assets at risk.
What Do I Need?
What you want to do with video dictates to a large degree the type and size of the storage array that you’ll need. If you record to tape and then digitize that footage into your system for editing, then you already have a physical backup of your data. If you want to bypass tape and record services directly to hard disk via a video capture board from AJA or Blackmagic Design, for instance, you’ll need a stronger data-protection plan. Planning to create sophisticated productions with several video and graphics layers? Transfer speed is what you need.
What about long-term storage? If you’re planning on keeping those ever-growing video assets for more than a year, you might want some deep storage—tape-based or DVD-based—that’s cheaper to expand than your primary external array. Got a whole team working on a single project all at once? Networked storage could be helpful. Keep these questions in mind as we dig deeper into the technology.
A good first step: consult a local systems integrator or reseller who has specified digital video storage systems for other churches. If you don’t know where to turn, ask a media director at a local church that’s using digital storage in ways that resemble your media department’s goals. Greg Golden, director of media ministry at Cottage Hill Baptist Church in Mobile, Alabama, has bought two storage arrays—a 1.8TB system and a 2.5TB system—from Ciprico in the last few years. Cottage Hill uses these arrays to record services directly, through a Blackmagic Design DeckLink Extreme capture card. Golden recommends that newcomers to the storage realm in particular should talk to a reseller before putting together a storage array themselves. “For my part, I didn’t fear going out there and spec’ing (the system) myself and just buying from across the country,” he says. “But you’d have to have pretty good nerves to do that.”
Acronyms Galore
But before you talk to a reseller, of course you’ll want to be as informed as possible about your choices. If you’ve poked around the Web to explore your external storage options, it’s likely you’ve run into a daunting collection of acronyms. DAS, NAS, SAN, RAID, SATA, SCSI … where to begin? People often talk of storage as if it’s a commodity, in terms of gigabytes per dollar, but the market really does offer a number of wildly different technological options. So let’s first take a step back and consider what’s important.
Every external storage setup contains a few common elements. Buy piece by piece, and you’ll need to make several choices: a chassis, a number of spinning hard drives and their capacities, a bus type, a RAID controller, and an interface to your workstation(s). That last element might require you to obtain a host bus adapter for your workstation.
The hard drives themselves come the closest to being a “commodity,” actually. The space is dominated by spinning hard drives, as solid state drives (no moving parts) have just come to market, and at a huge price premium (most notably as an internal option on Apple’s new MacBook Air).
Western Digital, Hitachi, and Seagate all make spinning hard drives, and they compete so ferociously that consumers reap the benefits of continually improved capacity, reliability, and power consumption. Last year, for instance, each broke the one-terabyte barrier for a single hard-drive unit.
The bus technology on the drives is much less cut-and-dried. On the direct-attached storage side, the technology has advanced from parallel ATA to serial ATA—SATA—as the dominant option, with SAS (serial-attached SCSI) as a high-performing option for larger servers. Got all that?
I’ll address networked, or shared, storage near the end. For most churches, direct-attached storage represents the sweet spot for typical church media departments in terms of cost, capacity, performance, and ease of use.
Transfer Rate
The transfer rate of your direct-attached storage system will determine how many streams of video your editor can work with in realtime without copying it to his or her internal hard drive. (That’s assuming, of course, your computer’s RAM and processors can handle all those video streams in the first place.) Bottlenecks can exist at a few different points in your data chain. An inquiry into that matrix is definitely outside the scope of this article, but here’s one example: SATA drives are rated at a transfer speed (ideally) of 375MB per second. A Sonnet Tempo SATA E4P PCI Express controller, which lets your computer connect to an external SATA array, is rated at a max transfer speed of only 240MB per second. Furthermore, real-world tests will probably yield much lower read speeds than that ideal.
When considering a direct-attached storage system, you typically have a few popular interface choices. There’s FireWire 400, FireWire 800, USB 2.0, and external SATA (eSATA). Modern workstations have connections for the first three, and eSATA generally requires a host bus adapter, which uses an open PCI Express slot or ExpressCard slot. FireWire 400 and USB 2.0 are rated at near the same peak read/write speed—49.13MB/s and 60MB/s respectively—but FireWire 400 has a better real-world sustained transfer, which is important for video playback. Depending on the video format you’re using, though, even a FireWire 400-connected external drive could suit your purposes. A stream of MiniDV is 25 megabits (not megabytes) per second, and FireWire 400 promises 400 megabits per second. Again, the best bet is to talk to a reseller with experience in this realm.
Protect your Assets
RAID stands for redundant array of independent disks. That “redundancy” means that you’re either mirroring your storage (effectively halving it) or striping it across several “independent disks,” which is the industry-standard method of protecting data against a physical drive failure. RAID comes in several flavors—0, 1, 3, 4, 5, 6, and 10 are common—and choosing the right one boils down to answering a few questions: How much storage you can dedicate to redundancy? How many simultaneous drive failures do you need to be able to withstand? Considering that a RAID configuration is likely to slow the read/write speeds of the drive, how much of a performance hit can your storage array withstand before it affects your editing performance?
“Depending on what they’re doing, we’re going to recommend a RAID 0 or a RAID 5,” says Barak Epstein, a senior account manager with Videotex Systems, a Dallas, Texas, reseller that puts together full video editing systems (including storage) for churches of many sizes. But if a drive fails, and you’re serving high-bit-rate video from the storage array directly, performance could take a hit large enough to affect playback. Ciprico, for instance, sells drives in a RAID 3 configuration, which uses a dedicated parity drive to keep the sustained transfer rate high even after one drives fails. For many applications, of course, that could be overkill.
If you’re buying an a la carte direct-attached storage system, you’ll likely be looking at hardware RAID controllers from companies such as ATTO. Ciprico and CalDigit make their own controller cards. Experts recommend against relying on a software RAID controllers or ones that are integrated on your computer’s motherboard.
It should be noted that RAID protection generally does not protect your system from data loss due to virus or human error—it’s designed to ensure against physical disk failure, a somewhat rare but often catastrophic occurrence.
Networked Storage
Networked storage has long been the province of very sophisticated video production facilities, typically television news stations and broadcast postproduction houses. A NAS (network attached storage) or a SAN (storage area network) is typically quite expensive, but there’s also the challenge and expense of maintaining a storage network.
Before investigating networked storage any further, ask yourself a question: Do I have several people—a graphics artist, an audio editor, and a video editor—working on the same material all at once? If the answer is yes, then a storage network certainly can make life easier for all involved. A typical SAN uses a Fibre Channel topology (4Gbps, often) for ultimate transfer speed. The administrator can allocate storage and throughput to different users.
Don McDonnell of Ciprico says that he has yet to see demand for shared storage from church clients, unless it’s a larger church doing very sophisticated television production. Still, that type of church is certainly out there. But even if the need is there, a traditional SAN might not be the best solution, considering all the management involved. Epstein of Videotex warns, “Having a SAN pretty much requires you to have a full-time IT guy on staff.” He recommends considering a solution like a Facilis TerraBlock, a SATA/Fibre Channel networked storage system that is designed with video-oriented users in mind—not IT guys.
Trevor Boyer is a freelance writer living in Brooklyn, New York. He likes to write professional A/V and video production stories (like this one) that can be reported via subway travel.
