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MillimeterSANs for Post
Apr 1, 2002 12:00 PM, By Philip De Lancie
With the increasing dominance of nonlinear editing and computer-generated effects over the last decade, storage networks for digitized video have become a crucial concern for every post facility. Initially the sheer size of video streams made capacity and throughput the major issues, but falling prices for bigger, faster drives have diminished those concerns. These days, it's not simply a matter of having enough storage; the core issue for a post facility is how the performance and flexibility allowed by a given storage configuration impacts overall facility workflow and productivity.
An Ethernet Local Area Network (LAN) clearly offers major improvements over the low-tech “sneakernet” approach that arose with the advent of removable hard drives. With a LAN, you avoid the risks of loss or damage associated with the physical transport of magnetic media from place to place. Instead, you keep a master copy of the project on the network server from which individual users download files to their local drives at the start of each session and to which they upload their work product at the session's end.
Unfortunately, this continual downloading and uploading of large files (video and associated audio) can take quite a bit of time. That drags down productivity and also makes it awkward to move projects from room to room to optimize utilization of a facility's resources. At the same time, to keep track of all the files going back and forth, you have to implement a strict version-control scheme and then hope that everyone working on the project follows the scheme religiously. Thus, while a LAN is a big step forward from sneakernet, it doesn't remove every barrier to the efficient movement of video data within a multi-room facility.
Over the past several years, a more advanced approach has been offered by a Fibre Channel Storage Area Network (SAN). Unlike even Gigabit Ethernet, Fibre Channel's high throughput reliably supports realtime playback of uncompressed video streams. And because a single storage volume — generally multiple hard drives in a RAID (Redundant Array of Independent Disks) or JBOD (Just a Bunch Of Disks) — appears to each user as local storage, SANs are free of the downloading and version-control hassles that can make LANs cumbersome.
As might be expected, there's a price tag attached to the benefits offered by a SAN. It's not only that SANs are more expensive to purchase, but also that there is little consistency among manufacturers in terms of how NLEs and SANs integrate into a total solution and what that solution allows you to do. That means that facilities with multiple NLE brands may find that a SAN designed for one won't work with the others, thus undermining the ideal of a single network over which all systems can collaborate.
While users and resellers may wish for greater uniformity across SAN implementations for video, more and more facilities are nonetheless embracing the technology. Have their SANs delivered on the promise of a more efficient workflow in post? To find out, we asked a few facilities to share their observations. Included below are the thoughts of William (Billy) Baldwin, chief operating officer at Postworks, New York; Philip Gershwin, manager of information services at Aspect Ratio, Hollywood; and Kal Hassan, director of engineering at ABC's WLS-TV, Chicago.
Millimeter: What areas of postproduction are served by your SAN, and what were the motivating factors that caused your facility to make the investment?
William Baldwin: We are a unique shop in that we have both in-house facilities and a large rental department. We got involved with Avid's Beta program for its Unity system, and our first jobs with the system were driven by the needs of our clients, one of whom wanted to capture at broadcast resolution and edit with five systems set up in Rome, New York, for the Woodstock Festival. We also installed Unity systems in our two facilities, more for our own piece of mind than anything. We now own five Unity systems total for rental and our facilities.
Philip Gershwin: Aspect Ratio is a motion picture marketing firm, which means that we make movie trailers, TV spots, and radio ads. We have 22 offline edit bays, both Avid and Final Cut Pro. Having come from a more corporate setting, the idea that each edit bay was its own independent island was insane to me. Why spend hours loading the same movie into each system when all systems can read a shared file in a common location? So we invested in a solution from Rorke Data.
Kal Hassan: WLS-TV has four Avid Media Composer editing units used for programming and promotions. One of the Media Composers is used for editing the Ebert and Roper show, which we tape in-house. In addition, three Avid MC Xpress units are used to record the show directly into an Avid Unity SAN with approximately 2TB of hard-disk storage. We use a Marquis software package to control the Xpress units from the production control room. This gives the show's producers instant access to a switched feed and two camera ISOs, which has proven to be a very efficient way to record the show. It's almost tapeless, except for a backup recording done on Sony SX [a digital ½-inch tape format]. Without the capacity provided by the SAN, it would be impossible to record multiple shows during one taping session.
Millimeter: What were the most important requirements and choices you faced in tailoring the SAN to the specific needs of your facility?
Baldwin: Before we were involved with the Beta program for Unity, we owned both the Avid and Transoft Fibre Channel solutions. Nothing comes close to Unity as far as meeting all of our needs: compatibility with NLE systems, number of seats, bandwidth, et cetera. It is server-based, not partition-based. And a switch is always better than a hub when you have an entire facility needing online bandwidth.
Also, staying within the Avid family is extremely essential when you consider upgrades. I could tell you horror stories of facilities that had bought a system from Transoft — who is now officially owned by HP — and then wanted to bring online the latest and greatest Avid Symphony system. Unfortunately, the Transoft didn't talk with systems that run on Windows 2000. Avid, on the other hand, upgrades all its systems together.
Gershwin: My personal philosophy is a simple one: keep your data as generic as possible. Avid and its Unity solution maintain a proprietary format that only other similar Avids can read. That was of no interest to us. After a lot of research, we chose Rorke for three reasons. One, we had a long history with them as the supplier of our drives for the sound and graphics department. Two, their drivers were written by Atto — another manufacturer with which I had had a long relationship. And three, they were the least expensive.
Continuing with a consistent philosophy, we also chose to go with JBOD over RAID for our storage. RAID is very expensive and provides a single point of failure unless you have a second RAID card, which makes it even more expensive. A RAID tower with two RAID cards will add about $15,000 or more to your bottom-line cost. Plus, it increases seek time and reduces bandwidth. But more importantly, it adds another level of complexity to an already complex environment. Instead of a RAID, for $4,000 I was able to set up an equal amount of IDE drives that maintain a mirror of all the data on the Fibre Channel drives in the JBOD.
As for the rest of our SAN system, we have two Vixel 16-port switches, Atto FC cards, and a Rorke Galaxy 55 tower with 12 180GB drives.
Hassan: The technical choices were determined by the equipment we purchased. It's not like you have a choice with some of these systems. Avid uses JBODs in their Unity SAN product. By contrast, we use Discreet Edit units in our high-end news editing rooms, and the Discreet SAN connected to these units has approximately 1.8TB of RAID 5 hard-disk storage.
Millimeter: How has the SAN changed your workflow? What does it allow you to do better or faster than before?
Baldwin: The SAN allows us to take on more work because it gives us much greater flexibility. It is greatly beneficial for turning a room around between jobs or sharing among multiple rooms without all the headaches of sneakernet and physical management of media. We can turn the rooms around faster or open a client's project in another room if they need to come back and make changes.
Gershwin: The SAN reduces our total storage needs, reduces the bottleneck of loading media, and gives us much-needed quality control. But most of all, it gives us the ability to move projects instantly from bay to bay as needed. An additional factor in our case, however, is the fact that the implementation of Fibre Channel was simultaneous with our conversion from Avid to Final Cut Pro. So it is hard to answer how one of these affected us without discussing both. The bottom line is that we used to have 18 editors and 10 assistants; now we have 22 editors and six assistants.
Hassan: In the case of the Ebert and Roper show, for example, we have been able to use the new technology to make the show better. The show has a short turnaround, and the nonlinear editing process supported by our SAN gives the team extreme flexibility in assembling the show.
Millimeter: What, if any, are the limitations or unexpected downsides of the SAN?
Baldwin: We wish it was easier to support our SGI-based systems better. This is more of a limitation created by Discreet's proprietary architecture than that of the Symphony. However, we are able to have our SGI-based system on the Unity by use of Avid's Port Server, which acts as a portal for any of the systems in the facility to mount Unity volumes.
Gershwin: The single biggest problem is that one only person can write to a partition at one time. Other than that, since we are 100% Macintosh, I look forward to OSX support.
Hassan: Like most things, SANs do have some limitations. For example, there is no archive solution as yet for our Avid Unity, although we have been told one is forthcoming. We are in the early stages of our industry's migration to digital and by extension to SAN solutions, so we tend to still back up critical things on tape. SANs are not yet as robust as we would like them to be.
Millimeter: How has your investment in the SAN worked out from the business perspective?
Baldwin: We originally thought that the Unity only had potential benefits for our engineering staff; we didn't see it as a profit center. The truth is that we are able to charge for the time we archive individual projects on the server. So in the end, we have actually made money.
Gershwin: We have had the system for about eight months. We spent less than $80,000 to get 2TB of storage shared between 22 edit bays. I see this as a minor investment when you consider that a single Digital Betacam deck cost us $40,000, and a single Avid bay cost about $100,000.
Hassan: I wouldn't call the investment minor. However, the prices are dropping dramatically. For example, our first JBOD in the Unity system used 50GB drives. The later ones used 73GB drives. Some SANs are shipping with 180GB drives. The newsroom automation system from Grass Valley Group will use Profile XPs and a MAN [Media Area Network] with 180GB drives. The larger-sized hard drives dramatically lower the cost of the SAN/MAN.
Continue the discussion on “Crosstalk” the Millimeter Forum.