Beware of storage performance guarantees

Ah, nothing to bring joy to the holidays like a bit of good old-fashioned sales craziness.

Recently we started seeing weird performance “guarantees” by some storage vendors, who seem will try anything for a sale.

Probably by people that haven’t read this.

It goes a bit like this:

“Mr. Customer, we guarantee our storage will do 100,000 IOPS no matter the I/O size and workload”.

Next time a vendor pulls this, show them the following chart. It’s a simple plot of I/O size vs throughput for 100,000 IOPS:

Throughput IO Size

Notice that at a 1MB I/O size the throughput is a cool 100GB/s 🙂

Then ask that vendor again if they’re sure they still want to make that guarantee. In writing. With severe penalties if it’s not met. As in free gear UNTIL the requirement is met. At any point during the lifetime of the equipment.

Then sit back and enjoy the backpedalling. 

You can make it even more fun, especially if it’s a hybrid storage vendor (mixed spinning and flash storage for caching, with or without autotiering):

  • So you will guarantee those IOPS even if the data is not in cache?
  • For completely random reads spanning the entire pool?
  • For random overwrites? (that should be a fun one, 100GB/s of overwrite activity).
  • For non-zero or at least not crazily compressible data?
  • And what’s the latency for the guarantee? (let’s not forget the big one).
  • etc. You get the point.
 
Happy Holidays everyone!
 
Thx
 
D
 

 

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