At the cornerstone of China Central TV’s digitized operation is a StorageTek PowderHorn 9310 tape library with five T9840B and five T9940B tape drives.
Content digitization, HD programming and broadband distribution have brought unprecedented challenges and opportunities to broadcasters. The conversion from an analog to a digital workflow has required new system architectures along with new investments in equipment. Meanwhile, the emergence of hundreds of new channels has increased viewer options and the opportunity for greater advertising revenue.
All of these changes mean that content producers and broadcasters need to handle more data and store larger files. Fortunately, IT and computer technology have provided users with a new variety of solutions.
One of those solutions is the storage of these increasingly large files as data on tape. The implementation of digital technologies has created new work-flows with the result of dramatically improved productivity and efficiency. Archived video clips now can be located and loaded with just a few keystrokes, instead of manually searching through the shelves in a video archive library. Viewing and editing stations no longer need to manually handle cassettes, eliminating a major source of potential loss. And, with digital storage, multiple users now can access the same content simultaneously.
Storing content
Simplified indexing and asset management, enhanced workflow processes, automation of broadcast servers, and the implementation of useful data protection policies are vast improvements on the previous ways content was handled. However, the most basic function, storage, remains key.
Given the size of digital video files, data storage, as opposed to video storage, is one of the most critical components of today's new architectures. Data storage has many benefits.
There are a variety of tape technologies to choose from, including AIT and S-AIT, DLTtape, LTO, 3592 and 9940 tape formats. These formats provide a variety of storage capacities and performance (access and transfer rates), all with high reliability and compatibility, creating cost-effective content protection solutions.
Scalability
Most of today's content processing takes place from hard disks. Servers provide the needed high-speed, multi-user access that news and promo production requires. Large disk systems also can handle the graphics files needed for effects and film projects. However, hard disks have their own limitations in terms of scalability, reliability and cost. Let's examine some of these issues.
As a “fixed” storage medium, increasing system storage capacity usually requires adding new drives and controllers, or replacing the old drives with more storage per disk. This is expensive and complex, no matter the vendor. And, many expansion paths require the storage to be “squared” in terms of size, bandwidth or both. Often the user can't simply add a few gigabytes of storage to a server without actually doubling the current amount of storage. This may also require additional bandwidth, which may require Fibre Channel switches and networks.
Reliability
With tape storage, users can scale up a storage system more ably. The initial investment in drives and libraries can be incrementally expanded through additional tape cartridges. No more upgrades via forklifts!
Cost
Computers, even professional systems, can suffer failure — perhaps even developing the dreaded BSOD. This is where the reliability of tape comes in. Content that is lost or damaged isn't content that can be used or sold. Tape allows content to be safely stored in a reliable, long-term, stable environment, thereby protecting it against failures such as destructive computer viruses and worms. Unlike hard disks, tape has a long history, more than 50 years, which certainly qualifies it as a reliable, long-term storage solution.
Figure 1. Enterprise disk, optical disk, performance disk and tape are the four common storage technologies. Of these, data tape continues to be the most cost-effective. Click here to see an enlarged diagram.
While the cost of hard disk storage has declined over the years, it is still more expensive compared to tape. Figure 1 compares storage costs for four common technologies. Let's compare the numbers.
Enterprise disk storage is 20 times more expensive than the cost of tape storage. Even a lower cost/performance disk technology, such as SATA, is still four times more expensive per gigabyte than is the cost of tape.
Capacity
Typical storage costs for a high-performance disk storage system run in the $2000 to $4000 per terabyte range. In contrast, storing that same content on data tape can be much less, as little as $400 per terabyte — that's one-tenth the cost of disk storage. This means a data tape can store about nine hours of 50Mb/s video for less than $10 per hour.
Tape also excels in terms of storage density. Today's feature films demand significant storage capacity. For instance, a finished feature film of 2K resolution requires about 2TB.
The generated work product for a feature film with 2K resolution typically needs between 10TB and 100TB of storage. A finished feature film providing 4K resolution requires 8TB of storage. Any facility attempting to create workstations with this kind of storage capacity on disk will quickly see how expensive it can become.
Reliable solution
Here are some other storage factors to consider. As film makers move into 4K production, storage needs don't double; they quadruple! The generated work product for a typical feature film in 4K resolution requires between 40TB and 400TB of accessible storage. A finished HD program running at 50Mb/s uses 23GB per hour of storage.
Tape's future
Analog and digital video tapes have long been a staple for broadcasters and content producers. Historically, no other medium could cost-effectively store the huge amounts of content created daily. Broadcasters are finding that truism still holds for digital images when they are stored on data tapes. Also, data storage tape formats are significantly less expensive than their video cousins, yet still provide high capacity, fast throughput and data reliability.
Today's tape technologies are experiencing solid market growth due to continuing improvements in capacity, performance and reliability while maintaining a cost-reduction curve that remains well ahead of other storage technologies. Mid-range and enterprise-class tape products support a wide range of storage applications, including long-term archival and preservation, data acquisition, disaster recovery protection, and mass storage for rich media.
Based on the roadmaps of the leading tape storage manufacturers, tape will continue to be more than three times more storage-efficient (six times with compression) than hard disk storage. And data tape's high-speed transfer rates allow content to easily be stored in streams, providing quick and easy access.
Many disk storage solutions claim to protect your content, typically through RAID solutions. However, recall that most also offer to back up your data from disk to tape — just in case “something happens.”
The bottom line is that without tape, your data could be at risk.
Rich Harada is president of the Tape Technology Council,www.tapecouncil.org.
