All-Flash
Storage systems that employ all-flash architectures use only a single type of media: flash. Because of this they are very fast. But, they are also expensive, making them suitable only for those applications where speed at any cost is the driving motivation.
Enterprise storage systems serve two functions – providing read/write access to the data (where speed is important) and storing data (where speed is less important). At any given time only a portion of a storage system's data (the working set) is being read or written by applications, while the remaining data is cold.
Since all-flash systems use a single type of media, all data – even colder data (data that is inactive) – is kept on flash media. This colder data is either stored on expensive flash – which has a higher write endurance – or on less expensive flash – which requires sufficient reserve (larger amounts) to deal with its lower write endurance. Therefore, even though flash does not offer much benefit for storing cold data, all-flash systems still use it to do so. All-flash systems try to compensate for this by supporting in-line dedupe and compression to reduce the systems' effective cost. But even with in-line dedupe and compression, all-flash systems still cost too much for broad deployment. Think of all-flash systems as the private jets of the storage industry. They might be suitable for some applications, such as flying your CEO to important meetings around the world, but for commuting to work on a daily basis, they don't make economic sense.
Flash Storage Architecture: What's Available and Why It Matters
Flash Storage Architecture: What's Available and Why It Matters
Everyone in the storage market is excited about flash. As well they should be. Flash can deliver much better performance than spinning disks. In addition, the cost of flash media is starting to come down to a level where all enterprises should consider adding flash-based storage to their enterprise storage infrastructure.
Yet amidst all this excitement there is also confusion. In particular, as vendors introduce a variety of all-flash and hybrid-flash storage systems, many storage administrators are confused as to the differences between the systems, as well as the benefits and drawbacks of each of them. Almost all current products in the flash storage landscape can be broken down into four different types of system architectures – all-flash, post-process tiering hybrid, caching hybrid, and continuous tiering hybrid – each with its own unique characteristics.
By comparing flash storage architectures side by side, storage administrators can better understand what flash architectures – and by extension what flash products – make the most sense for their particular set of applications. In doing so, they are likely to find that while flash has improved enterprise storage system performance, until recently storage system architectures have failed to keep up with media and other technology advancements, and fully leveraged these technologies to deliver better performance while minimizing data storage costs.
In this slideshow, Jacob Cherian, vice president of product strategy at Reduxio, takes a closer look at the four flash storage architectures currently on the market.
