Case Study: The broadcasting group integrates a prototype disk system with its multitiered storage.On Oct. 21, 2005, turner entertainment networks, a division of the Turner Broadcasting System, ran a very special promotion for the National Basketball Association on TNT, or Turner Network Television. To viewers, the promotion didnt look any different.
But to broadcasters, it was quite unusual in that the video was loaded from a holographic disk and then broadcast through Turner Entertainments multitiered
storage-to-air system. It was a first for the broadcast industry, said Ron Tarasoff, vice president of broadcast technology and engineering at Turner Entertainment.
"A lot of the storage para-digms in the computer industry and data industry are now being ported over to broadcast because everybody is going digital," said Bill Wilson, chief scientist for InPhase Technologies, in Longmont, Colo., the manufacturer of the holographic read/write drives and media that were responsible for the successful test at Turner Entertainment.
The concept of holographic storage was developed 30 years ago. And according to storage analyst Tom Coughlin, president of Coughlin Associates, in Atascadero, Calif., and organizer of the annual conference Storage Visions, InPhase is the first company to bring a reliable holographic storage solution to market.
In October 2005, Wilson flew to Atlanta with the companys prototype drive to see how holographic storage could work with Turner Entertainments highly controlled five-tiered video content storage system. At the time, he admitted the proto-type was just a bit bucket with no application software to manage the content. Wilson was there to understand how the broadcast industry stored and moved content. He wanted to learn how his storage device could best be configured to work with a broadcast system.
Tarasoff was eager to see if the drives could operate as an added tier of storage attached to his five-tiered storage system. He explained the configuration in great detail.
At the top are the Turner Entertainment networks Pinnacle MediaStream edge servers, with a current storage capacity of 87TB, that play the programs out to air across the various networks. Any content Turner Entertainment receives on videotape is first loaded into the system as a digital file.
The second tier consists of EMC Clariion Fibre Channel disks, with a storage capacity of 22TB, that hold all broadcast programming needed for the next seven to 10 days.
The third tier of drives, consisting of EMC Serial ATA models with 4TB of storage capacity, is used for program prestaging. Content that will be needed in about a month is pulled out of deeper storage and placed on spinning disks. All active short-length material, such as Turner Entertainments 26,000 commercials and 29,000 promotions, is held in this tier of memory for its entire broadcast cycle.
The fourth tier comprises ASACA TeraCart DVD-RAM disks from Shibasoku Corporation of America that have a current storage capacity of 22TB and act as backup storage for all the active commercials and promotions.
The fifth tier, consisting of Sun Microsystems Storage-Tek data tape robots and drives with a storage capacity of 1.3 to 8.86 peta-bytes, acts as the long-term storage tier for programs and movies.
While Turner Entertainment still receives plenty of content via videotape, more and more content starts as a digital file. For example, about 85 percent of the 26,000 commercials in Turner Entertainments active library arrive as digital files, Tarasoff said.
Storage is slowly growing as well. "Anytime a program is aired successfully, it is scavenged back from the play-to-air server as a file and then archived onto data tape. So that each day that goes by, more and more content is being archived [digitally] onto data tape," Tarasoff said.
InPhases optical disks have some obvious benefits for digital video storage. They deliver random access, high storage capacity (300GB) and high throughput (160M bps). Currently, those numbers are still below the storage capacity of data tape (500GB) and its throughput (960M bps), said Tom Inglefield, media and entertainment solutions manager for the Data Management Group at Sun Microsystems. Inglefield said, though, that there soon will be a crossover point when holographic technology surpasses tape in storage and throughput.
InPhase said it believes that will be sometime around 2010. The company predicts storage on a single piece of holographic media will rise to 1.6TB, with throughput reaching 960M bps.
Although Turner Entertainments data tape media library currently can handle its long-term storage demands, Tarasoff always is keeping his eye on the next big thing in storage and is willing and eager to test.
The reason holographic disks are able to pull off these amazing feats of high storage and fast transmission speeds is their ability to hold more than one piece of information in a single location. A DVD is a series of mirrors, each representing a single bit. At that same location, a holographic disk holds a series of checkerboard patterns of information that change depending on the angle that its read. Its just like how the image of a hologram changes as you look at it from different angles, Wilson said.
There are some additional, less obvious benefits to holographic storage. As the networks move to dealing with more high- definition content, with a holographic disk, Tarasoff said, theyll be able to store a 3-hour movie easily on a single piece of random access media rather than dividing it up across multiple media. Plus, he said, a holographic disk will be easier to ship than a videotape or hard disk drive.
Coughlin said he believes there are some psychological and sociological reasons the broadcast industry is finding holographic optical disks an attractive option. "There is a certain bias against using tape, even though its digital. There is a natural inclination by many people because of that history to look at nontape options," Coughlin said. In addition, Tarasoff fears that tape wont last as long as optical, which, he said, has a rated shelf life of up to 100 years.
Turner Entertainment has ordered four drives from InPhase and plans to test them as an added sixth layer to its five-tiered storage system. Tarasoff said he has no immediate plans to phase out the fifth tier, data tape storage.
David Spark is a freelance writer in San Francisco. Contact him at david@davidspark.com.
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