Considerations common to any workflow
First, the storage system must enable efficiency throughout the workflow, enabling staff to achieve greater productivity. While traditional tape-based workflows developed at the speed of real time, file-based flows provide faster ways of working than real time, freeing up resources and people who can accomplish other tasks in the time leftover. Also key to this type of productivity is the storage-system's ability to give users and applications access to the media they need without being subjected to time-consuming bottlenecks.
In addition to supporting faster workflows, the storage system must provide a better user experience than it did with tape, with equal or higher performance, and simultaneously in support and interoperability with all customers. Figure 1 illustrates how critical storage is to the performance of other systems throughout the workflow. The storage system must also provide absolute data availability and uncompromising reliability. Frequently installed in environments where the proximity of the outlet to the air or production time are critical, storage systems must be able to make the necessary means available exactly when they are required. Producers and other users cannot wait for the storage system to finish their jobs.
As with any other infrastructure investment, storage must be cost-effective, offering real, measurable ROI in operational and productivity improvements.
Media-specific considerations
File-based, media-focused workflows place unique demands on the storage infrastructure, and unless the system has been designed to handle these requirements, application bottlenecks and limitations can occur. Therefore, it is vital to consider how well a storage system can meet the various media-specific challenges.
Bandwidth is king when it comes to media workflows. An assessment of the inputs, users, and output outputs required by a typical workflow shows that an immense amount of storage system bandwidth is indispensable. On the ingest side the system must be able to handle all incoming loads simultaneously. It must also give all users of the application — publishers, proxy viewers, QA staff, and others — unrestricted access to such content, regardless of how many more are using the system. Figure 2 illustrates the bandwidth demands placed on a typical storage system.
On the distribution side, and as the industry evolves, the growing number of content delivery points requires the system to be able to constantly power different devices, without interruption. A good storage system offers cost-effective bandwidth (measured in dollars per gigabyte per second) and can be easily expanded to provide the additional bandwidth required to accommodate the volume of work that naturally arises with the launch of new projects and services.
The second critical element is the storage system's ability to support an active workflow. In any media workflow there is some element of real-time activity, for example video recording or playback. This means that the devices – servers, encoders and set-top boxes – connected to the storage system must be tightly integrated so that, to the extent that the content is recorded to the system, the file can be written to the storage system without delay, and clients can access it even during the recording process itself.
Latency is an important feature because it determines how well certain production applications will perform when connected to the storage system. If an installation has adopted an on-site editing model, in which content remains in central storage during the editing process, then the system must be able to maintain low latency access over the network while publishers work on the content. As the number of users grows, the system must be able to support their work, without loss of frames or otherwise interrupt user activity.
The availability and reliability of stored media is of vital importance within most production environments. In a news service, for example, the workflow depends on those factors. Multiple online sources may be continuously sending loads into the ingest process, while production customers want to immediately start working on the content, especially when it comes to breaking news. The speed with which they can finish a story dictates how quickly it can be published on the broadcast infrastructure and aired. Any interruption in access to the stored content or to the ability of a publisher to access the input material may end in a missed opportunity.
The ability of the storage system to handle failures of some component also contributes to the continuity and quality of service. Hard drives fail, and they need to be replaced and your data recovered. All storage systems provide a mechanism to do that, but not all guarantee the availability of the ongoing system or performance during a component failure or the reliability of the data resulting from the rebuild process. Rapid recovery and high performance during recovery will minimize the impact of failure in a fast-paced production environment.
Storage systems that integrate media processing can simplify and accelerate workflows by eliminating content transfers to and from external systems. Storage that includes individual servers interconnected with standard networks may have additional processing cycles that can be used for tasks such as transcoding. For example, content moved to the storage system can be automatically transcoded to other formats, making it more readily available in the required formats for when needed, and eliminating transfer times to external encoding servers.
The last essential attribute in storage for file-based workflows is the degree to which the system actually understands that the stored data is media and is able to present information about the content in a more meaningful way than a conventional view of a file system. With a more sophisticated view of content assets, often a complex set of files with multiple video versions, multiple audio tracks, and ancillary data, the user can examine the system, search for content, and move it between applications, more effectively. Systems that possess intrinsic content knowledge not only streamline media management, but also improve workflow efficiency for users and for dedicated third-party applications to manage content within the storage infrastructure.
Conclusion
Storage provides an essential foundation for file-based media workflows, and for these flows to be effective, the system must be optimized for tasks associated with media flows. By expanding the possibilities of users and adding value through greater functionality, installing the right storage infrastructure saves time and money.
