RAM Sizing Guidance for SmartTiers™

SoftNAS® SmartTiers™ provides the ability to seamlessly move blocks of data from high performance, low latency storage to more economical, larger capacity storage based on the value of the data. In order to ensure this seamless, high performance transition of data, SmartTiers has additional RAM requirements when compared to a basic SoftNAS deployment.

Any SoftNAS system that will use SmartTiers™ should automatically include an extra 4 GB of RAM for the instance/VM, to account for overhead. This is a onetime 4GB RAM increase in addition to the RAM normally associated with the SoftNAS instance. This 4 GB of RAM is applicable regardless of the number of SmartTiers™ pools allocated for use on the instance.

In addition to the 4GB of extra RAM, an extra 64MB or RAM should be included for each 1TB of storage to be included in all of the SmartTiers pools (cumulative).

For example: 

  • 1TB of SmartTiers Storage: 4GB + 64MB of extra RAM
  • 10TB of SmartTiers Storage: 4GB + 640MB of extra RAM
  • 20TB of SmartTiers Storage: 4GB + 1.28GB of extra RAM
  • 50TB of SmartTiers Storage: 4GB + 3.2GB of extra RAM

RAM requirements for your SoftNAS instance can be found under System Requirements for the platform in question, but are highlighted below in order to keep calculations simple.

Minimum requirements for a production workload is typically calculated at 8 GB of RAM for a simple SoftNAS Deployment. An additional 1 GB of RAM is suggested for each terabyte of deduplicated data.

The complete calculation for a SmartTiers enabled instance of SoftNAS would be: 

8 GB + 4 GB + (1GB x xTB deduplicated data) + (xTB of SmartTiers Storage x 64 mb)

for example:

25 TB of Deduplicated SmartTiers™ data: 8 GB + (1 GB x 25 TB = 25 GB) + 4 GB + ( 25 TB x 64 mb = 1600 mb) = 38.6 GB RAM