Choose storage that supports device longevity

There are several low-power memory storage options that are suitable for IoT devices due to their energy-efficient characteristics. When choosing storage, the use case and workload dictates much of the decision. For example, for a device that is deployed to a harsh environment that is not easy to access, choose storage that is durable and resilient.  Also consider the wear and tear on flash memory due to the workload, and its impact on device longevity.  Provision the amount of storage beyond current requirements for the application to allow for additional use cases in the future, thereby extending the device's useful life. In summary, the appropriate type and amount of storage for the device application should be carefully chosen as it can have an impact on the operational phase of the device as well as the overall cost.

File system choices can impact processor and memory requirements for the device, in turn impacting the power draw and ultimately sustainability. Choosing a lightweight file system such as littleFS or Reliance Edge for embedded systems can help reduce power consumption and increase the life-time of the storage through features such as wear leveling, power-efficient file updates, power-safe operations, small footprint, and customizable configuration options.

For IoT use cases that demand higher power edge gateways, various disk drives or solid-state drives may also be used. Using techniques like RAID, though more power intensive, can improve the performance and resiliency of gateways or servers and in turn improve the overall sustainability of the system by reducing the need for truck rolls.

A key consideration for storage selection is to support dual partitioning of persistent storage for Over the Air Update (OTA) capability.  In addition, the flash subsystem must be capable of independent erase and write operations for each partition (or image block).

When deciding on storage options for a use case, satisfying just the requirements of the application will not always be the most sustainable practice. Think about the performance of the storage over the life of the device, whether the device has enough storage to support buffering/analysis of data to alleviate the need to transmit, and if the storage supports extensibility and longevity of devices to reduce the operational impact and carbon footprint of upgrades and replacements.