How to Choose an All-Flash Array

April 5th, 2016
How to Choose an All-Flash Array

As of June 2015, Gartner recognized 13 vendors in their Magic Quadrant for Solid-State Arrays -- four leaders, one challenger, three visionaries and five niche players. All 13 vendors provide a roughly 10X IOPS performance increase as compared to spinning disk and submillisecond latency. With so many choices, and nearly identical IOPS and latency numbers, how does one choose an all-flash array that is best for them? If you are grappling with this question, then you may want to consider asking the below questions of your all-flash vendors.

Was the array originally built from the ground up and optimized exclusively for flash?
o You can either optimize the OS, RAID, etc. for spinning disk or all-flash, you can’t have it both ways.
Do you need scale up and/or scale out?
o What sort of growth do you anticipate over the next 3-5 years?
o If the vendor lacks scale out, then how easy is it to manage multiple arrays?
o What is the maximum capacity per array?
What type of flash drives do you use?
o As a side note, software has made consumer-grade flash extremely reliable. The trend is to use less expensive MLC as opposed to costly eMLC.  
Does the array offer QoS?
What protocols are supported – block, file, object?
What is the connection between the controllers?
What are the networking options – 16 Gbps FC, 40 Gbps Ethernet, etc.?
High Availability:
Does the array support full redundancy with hot-swappable everything?  
How does the array handle failure?
Is it possible to have performance degradation in the event of a controller failure or drive failure?  If so, by how much?  
Does the array provide non-disruptive upgrades?
o This should apply to all upgrade scenarios i.e., major OS, minor firmware, controllers, drives, etc.
How many nines of availability is your system rated to support?
What flavor of RAID is supported?
o How many drives can I lose in a single RAID group before I lose data?
Data protection:
Does the array natively support snapshots, clones and replication?
Do you have hooks into certain applications to provide OS application consistent snapshots?
How do I perform a restore?
What type(s) of replication is supported?
How can I move data to disk, tape and/or cloud?
Implementation and Management:
Can the array be installed within a couple of hours?
o Is it easy enough that a sales engineer can complete the setup?
How easy is it to use the array?
What sets your support organization apart from your competition?  
Is a proof-of-concept possible and with what configuration?
o One array or two (can you test replication)?
What level of commitment is required to start a POC?
How long is the lead time on a POC from signed paperwork to implementation?
Long-term viability:
Is the company viable and stable?
Are they going through a merger/acquisition that may cause certain products to be retired?
What is your company’s customer satisfaction score?  
Warranties and Special Programs:
Do you warranty the flash drives forever or will they eventually reach an end of life date?
Do you have a program that provides a controller upgrade?
Can I return the array for any reason within 30 days of purchase?
Does the array support thin provisioning, and more importantly, in-line deduplication and compression?
At what level of granularity is this occurring – 512B variable block, 4K fixed block, 8K fixed block?
o Good benchmarks are 5:1 data reduction for databases, 8:1 data reduction for VMs, and 12:1 for VDI.  I have one client getting 16:1 data reduction for an Oracle database environment, so mileage will vary.  You’ll definitely want to prove this out specific to your own data in a proof-of-concept (POC).
What is my cost per usable TB (after data reduction)?
o As a side note, my aforementioned client getting 16:1 data reduction for their Oracle database environment is essentially purchasing all-flash for the price per TB of tape.
How much money will I save in maintenance fees by migrating from a legacy spinning disk array to a new, all-flash array?
How much will I save in rack space, power and cooling?
Is there an additional cost for softwar,e or is all software included?
What happens when I have to upgrade my controllers?
Do you have a program that provides for a free controller upgrade every three years?  
While compute capabilities doubled every three years, and networking throughput increased tenfold (or more) over the past decade, storage really didn’t change all that much. We were still using the same 15K and 10K spinning drives. As a result, storage became the bottleneck within the infrastructure.
Although flash solved this problem and eliminated the bottleneck, in its early stages, flash was still very expensive. However, this has definitely changed. The proliferation of MLC drove that downward price curve, and optimization around data reduction has made flash so affordable that it is now very clear—The data center is going all-flash, it’s only a matter of when, and it’s happening sooner than you may think.  
According to industry experts, the cost per raw TB of flash will be even with the cost per raw TB of SAS in 2016, and this is before data reduction comes into play! With some of the data reduction results that I have seen firsthand, it is possible to acquire flash for the price per usable TB of tape—Remarkable indeed!  
Flash provides the strength to transform your business today and pave the road to the future. It gives you the power and reliability you need to tackle the most demanding business and IT problems. 

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