SAN: Flash it all or just the best bits?!

Flash storage - pure flash or hybrid?

One of the hot topics of the past few years that continues to garner interest amongst most IT departments is flash storage. Is it a case of simply putting in as much flash as you can afford, going a more generalised hybrid route, or abandoning the idea and using more traditional methods? Our in-house expert Phil Morley explains the good, the bad & the ugly when it comes to flash storage.

Don’t (always) believe the hype

flash can actually increase latency

Flash drives have transformed the reliability of higher end portable devices due to redundancy of spinning disks, making the idea of all-flash the nirvana for many a storage admininstrator. However, flash does come at a higher cost per GB that makes the performance and the cost prohibitive for many flat file applications.  Plus, while it is commonly acknowledged that flash is a top solution for databases, virtualisation, VDI and OLTP, it is perhaps less suited to mundane workloads such as file and print services and general archiving. 

Indeed, wrongly deployed, flash can actually increase latency and make worse the problem it was intended to fix: when wrongly configured or used for innapropriate workloads, adding a tier of flash adds an extra ‘hop’ between end user and the source of data, hence adding latency.

Old faithful or new kid on the block?

One of the biggest risks in diving into flash is not considering the cost of future upgrades. Most vendors, whether it be an established ‘legacy’ vendor or one of the many new young start-ups, will offer tremendous discounts on any initial purchase to hook in potential clients – but what guarantees do you have that the same discount levels will apply in subsequent years as you need to add capacity? 

Start-ups can be appealing for a couple of reasons:

  1. They offer extremely aggressive pricing in order to add new ‘Logo’s’ (customers) to their roster
  2. Some end users like to be early adopters of cutting edge new technology, making new kids on the block attractive

Conversely, other end users consider the new start-ups too much a risk: there are many of them and only a few will survive, either on their own or via a buy out (see HP’s acquisition of 3Par further back or Netapp’s more recent acquisition of Solidfire as examples). This means the possibility of being left high and dry with no support on mission critical kit should the vendor liquidate.

clients have pushed to one side their all-flash array (AFA) within a year... due to the ongoing cost of upgrading

Stretch that budget

When it comes to budgets, there are cases where clients have pushed to one side their all-flash array (AFA) within a year and purchased a brand new hybrid array of a much higher capacity due to the ongoing cost of upgrading with 100% flash. One of our new clients recently enjoyed better value spending their £90k storage budget on an brand new Hybrid Flash Array resulting in around 50TB usable capacity, as opposed to the same budgeted amount affording them just 10TB usable had they upgraded their existing all-flash array.

There are so many factors that go into choosing the right flavour of flash for your business. These topics will be covered in more depth in forthcoming blogs so make sure you are following this feed!


Phil Morley is a highly accredited Pre Sales consultant with 23 years industry experience, and is responsible for the design of client infrastructure solutions.