I recently attended an event by one of the big storage vendors, which had an interesting presentation by their senior technologists, i.e. one of those guys who get the big money for reading the tea leaves correctly as to where technology will be in 5 year’s time.
It included a statement about where Flash/SSD/EFD drives are today and where technology is headed. I remember two points that were made – the first one that we currently see a convergence of memory and solid state drives. Now that prices for SSD drives have come down considerably and are affordable within mainstream computers like desktops and laptops and their reliability is at least acceptable for normal use – and protected by seemingly more chips for error handling than for data use within enterprise flash drives. The gap between disk performance and speed of memory is beginning to narrow.
The second point made was that he could not see a serious future for SAS drives and was predicting for them to be obsolete within the next 5 years.
What is the best disk technology? I think the answer as so often is “it depends”. What are you trying to get out of the storage investment – are there performance requirements or are there capacity requirements? In my experience most of the time there is both, but they differ wildly – while for some environments the goal is “as much capacity as possible at acceptable response times”, other environments are trying very hard to get their response time down from 5 minutes to 4 minutes.
Several arrays nowadays can have a hybrid mix of disks installed plus – in some cases – internal memory-based cache, i.e. they can incorporate memory, EFD/SSD, SAS/FC and SATA and some advanced arrays are capable of moving data between these storage tiers, which actually leads me to the question “Who cares what the best disk technology is?”.
What do I mean by that? My recommendation is not to be dazzled by specs and technology – ultimately it does not matter, what type of storage is used and what it is called, as long as the used technology can satisfy the current requirements with some room for growth. Will it matter for most companies if SAS drives will be around in 5 years’ time? I do not think so – as long as there are spare parts for existing arrays, older arrays will eventually be decommissioned and be replaced with whatever will be around then. Does it matter if SSD drives contain NAND chips or something else? As long as they are reliable and provide the required performance: I do not think so.
It may be interesting for the companies producing storage arrays, but as an end user or a company you take the next technology refresh as it comes and install whatever fulfils the current requirements at the current required price point. And the only thing that we will know for certain is: Whatever will be the next array/disk technology, it will provide more capacity, it will be faster and it will not be more expensive.