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SSD to HDD Ratio

  • 3 October 2016
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Userlevel 2
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What is SSD to HDD ratio followed for nutanix?
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Best answer by Jon 4 October 2016, 04:00

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Userlevel 6
Badge +29
There is no perscriptive ratio that is "gospel" for us, it's all based on the application/workload requirements.

Some require a very high ratio, up to even 100% flash (i.e All flash system), whereas others are much more low impact and just require "storage" to exist, without any performance at all.

Do you have an example/requirement we could work through here?
Userlevel 2
Badge +17
Assume we suggested NX-3000 series box which has 2 SSD max capacity. due to budget constrain of customer BOM get changed to NX-1000 series which has single SSD max capacity. So first design we offer 2 x 480 GB SSD in later offer 1 x 800 GB per node. How it will impact?
Userlevel 6
Badge +29
Well, you can see the capacity impact very quickly using the designbrews calculator, which is pretty easy to use:
http://designbrews.com/

besides the capacity impact, theres a slight impact on serviceability, just takes a bit longer to recover from a single SSD failure on a single SSD system rather than a SSD failure on a dual SSD. No impact to data availability or protection, just know that the CVM's OS lives on that SSD too, so inessense we have reinstantiate that CVM upon disk replacement, and we've automated the vast majority of it, so its all good. SSD failures are pretty darn rare anyways, so its nothing to lose sleep over.