Kitplus - TV-BAY Magazine

To view this page ensure that Adobe Flash Player version 11.1.0 or greater is installed.

CONTENT (client). It is a natural consequence of the environment that due to factors such as concurrent requests for the same data, the nature of the write process or simply bad luck, as more media fi les are distributed across the storage nodes and as requests to read fi les are made, contention for access to the storage nodes will increase. And in this environment, contention is unacceptable because of the potential to slow down or delay access to a given fi le and the potential to interrupt processes like live playout or cause video or audio frames to be dropped when content is being rendered. Swift Read Technology To deal with the issue of contention, the fi le system monitors the performance of the storage nodes and detects which ones are responding more slowly and may delay read requests. Armed with this critical information, it can instruct a client device to read all of the data blocks associated with the requested fi le or, if a node containing data is experiencing contention and is likely to delay a read request, to skip that node and reconstruct the requested data using the parity information instead. By reconstructing instead of waiting for a slow resource, data can be retrieved at a faster rate than is normally possible in the presence of contention for storage resources. An added benefi t of this type of fi le system is that the same performance monitor that detects slow responses from a 50 | KITPLUS - THE TV-BAY MAGAZINE: ISSUE 102 JUNE 2015 storage node can also detect when a storage node has completely stopped working, as in the case of a hardware failure. Thus your fi le system is able to continue operation even if an entire storage node discontinues operating, offering you an unprecedented level of fault tolerance. Efficient Use of Storage The fi nal benefi t of a parallel fi le system is the effi cient way in which it makes use of storage resources and how that effi ciency increases as system size increases. In the case of the example in Figure 1, two storage nodes are used for data storage and one node is used for parity. Thus, the XOR 2 confi guration illustrated uses 2/3 of its storage resources for data and 1/3 for parity. In an XOR 3 confi guration, three nodes (3/4 of storage resources) are used for data and one is used for parity. An XOR 4 confi guration uses 4/5 nodes for data, XOR 5 uses 5/6 nodes for data and so on. Other high performance shared storage systems simply make duplicate copies of data to avoid contention and improve read speeds. This approach, known as mirroring, can at best use just 50% of storage resources. Make Sure You Look Under the Hood When It Comes to Selecting Storage So another step change is taking place in storage. A high- availability distributed fi le system for the masses was once inconceivable, but with the introduction of EFS it seems there is a solution on the market to allow facilities to grow their internal storage infrastructure securely and profi tably. It is important for facilities and engineers to take a closer look under the hood when evaluating their storage infrastructure. A high-performance storage system is not enough. You need smart fi le system management combined with user and asset management tools to effectively manage the media data road ahead of us.