Implementing Shared Storage For 4K+ Post Workflows

Beautiful 4K images are gracing movie theatre screens today, and will likely be in our living rooms soon, writes Jim McKenna, vice president, Facilis Technology, Inc.

As 4K, 5K and 6K replace HD on many shoots, most producers are either using some camera raw files in post, or at least considering it. We're even starting to see more facilities utilise camera raw files in the craft edit, because it allows them to maintain the highest possible quality throughout post and also avoid relinking issues.
However, there is still much confusion surrounding 4K, especially in regard to the best network infrastructure for supporting these large images throughout the post production chain.
One thing is clear: without a strong shared storage infrastructure in place to support all aspects of 4K+ post for each phase of a project, a facility will continue to run into bottlenecks that thwart creativity. Many facilities have overburdened their networks with R3D, ARI, DNG and MXF files that range from 300 to over 2500Mb/sec in data rate.
In the colour grading and compositing process, the creation of the uncompressed, de-bayered DPX file type is common. The data rate of these files can be more than 1200MB/sec (9600Mb/sec). These are the same networks that were deployed when DV25 was in fashion, and they're not ready for the influx of 4K+ files. These workflows require much more capacity, lower latency and a higher aggregate throughput than anyone was considering a few years ago.
The easiest way to lower latency and ensure bandwidth availability for all clients is to invest in a SAN or NAS with a custom shared file system, optimised for the type of data usage in your facility. If you're mostly concerned with getting consistent bandwidth for hundreds of render nodes to a single namespace (one drive letter or mount point for all network storage), you should invest in a system optimised for IOPS (input/output per second).
If you're more concerned with making sure that your multi-layer HD timeline doesn't drop frames, you'll want to consider a system optimised for large requests. There is no one-size-fits-all with storage networks, because the architecture to achieve diverse goals can be quite incompatible.
One of the biggest hurdles for post production professionals is overlooking the short term, and thinking about the long term. Some facilities fall back to DAS (direct-attached storage) when considering the architecture required for various project requirements.
This will help you today and maybe next week, but when the project grows, efficiency will suffer. There's no reason to believe that the same workflow advantages you have with lower bit-rate video can't be achieved with higher bit-rates. It just takes the right solution, and it doesn't have to be a 'heavy iron' system, or require IT expertise to massage and tweak various networking parameters.
Facilis has maintained Single-user Write functionality (block-level device sharing) alongside Multi-user Write through our shared file system, as a dynamic sharing method for our TerraBlock solution. When the opportunity arises to work with a particular format that is beyond the speed of Ethernet connectivity or outside Facilis’ shared file system support, our users can still utilise the storage they have for the job at hand by switching their project volume to a higher bandwidth sharing method over 16Gb Fibre Channel. Thus, the same storage being used for collaborative craft edit can serve as 4K DPX source for colour and compositing.
On the evolutionary path of post production, we're still in the early stages of 4K+ post. As processers continue to get faster, codec and file type support will widen and having a flexible shared storage system that supports the entire facility will become critical. Whether a boutique shop or large facility, an intuitive and reliable shared storage system that lets you DO IT ALL is a worthwhile investment.

The article is also available in the online edition of RFV here.

(IT/JP)