A file system is used to categorize information, allowing it to be stored in separate files and folders. For an embedded device, one of the most critical aspects of a file system is reliability – the device must always be able to boot up, regardless of when the power was interrupted.
 
Datalight file systems are designed for power interruption, and give the developer complete control over how much data is at risk with dynamic transaction points. Within the scope of this requirement, our savvy developers have worked to give the best possible performance, often on-par with non-reliable solutions such as FAT.
 
All of the products below are provided in source code format, and run in a variety of RTOS (Real Time Operating System) environments. Use the following chart to determine which product is the best fit for your design, then contact our Datalight sales team for licensing details.
 
  Reliance Edge Reliance Nitro Reliance
Reliability      
Technique used Transactional Transactional Transactional
Overall (power safe) Yes Yes Yes
Media failure detection Yes Yes No
Runtime control of transactions Yes Yes Yes
Time-based transactions No Yes Yes
Performance      
Mount after power interruption Fast, consistent Fast, consistent Fast, consistent
Sequential large read Fast Fast Fast
Read small files Moderate Fast Moderate
Large sequential writes Fast Fast Fast
Small random writes Moderate Slow Moderate
File system operations Moderate Fast Moderate
Deterministic latency Yes No No
System requirements      
Small Code Footprint Yes No No
Low RAM requirement Yes No No
Exchangeable Via Datalight
custom application
w/driver w/ driver
Development standard MISRA C: 2012 Datalight Internal Datalight Internal
Test suite provided Yes Yes Yes
Format and checker tools Yes Yes Yes
Internals      
Directory structure Linear Tree-based Linear
Maximum file size 256 TB 2 TB 4 GB
Maximum disk size 256 TB 256 TB 2 TB
Metadata CRC Yes Yes No
POSIX file permissions No Yes No
Case sensitive Yes Configurable Configurable
OEM attributes No Yes No