One Small Step to a Reliable File System

The Reliance Edge File System Essentials (FSE) is one of two API sets supported by Reliance Edge. It is a minimalist but reliable alternative to the POSIX-like option. What are its benefits and how does it work? This feature summary should answer those questions.

Key differences between SPI and Parallel flash media

Once thought to be in decline, raw flash media is definitely on the rise in embedded designs. A relatively new form factor using the Serial Peripheral Interface (SPI) has advantages compared to earlier (and larger) packages of parallel flash. This brief article mentions a few of these, comparing the two options.

Myth Busted - Overclocking NAND Is Easy

NAND clock parameters are not something set by the ordinary embedded developer. Usually they are provided as part of the BSP for the embedded hardware board. if your project makes changes to the NAND media, the processor, or even the length of the traces between those two components, these NAND parameters may be something you have to update to achieve full functionality.

On Utilizing U-Boot in Embedded Designs

U-Boot is becoming the defacto standard among embedded bootloaders, from Embedded Linux to VxWorks 7 and even small solutions such as FreeRTOS. How can proprietary software work in this GPL environment? How does a device boot from NAND using U-Boot? This blog post focuses on these answers and more.

Do You Need the Flexibility and Transparency of Source Code?

Acquiring software components for your embedded design can be a time consuming task. The right libraries can be purchased, but if changes are needed, the whole project may have to wait. On the other hand, a source code solution can require more knowledge, or even a dedicated resource. Which is the best solution for your design?

Splitting hairs: When is a flash file system not a flash file system?

When you spend as much of your time as we do in the depths of the storage stack, you become aware of nuances that are lost on those less well-versed in file systems and media drivers. Some products call themselves "flash file systems" yet offer absolutely no features that have anything to do with the flash memory. "How can that be" you ask, "are they lying?"

Effective Power Interruption Testing - USB Removal and NAND Corruption

We had some excellent questions in our April web seminar. These answers delve into removing USB media and corruption on flash media.

Partitioning - Slicing the Options

A file system is a common way of addressing the storage media; partitioning is a method for slicing that media up to use multiple file systems or multiple instances of the same file system, to support different purposes. This article breaks down two methods for partitioning the data.

Do you need a file system or a flash manager?

I am sometimes asked what the difference is between a flash manager and a file system. In broad terms, both are required to store data on flash media, but their roles in storing the data vary greatly from one another. Simply put, software management controls how the flash media is read from and written to, while a file system dictates how and when data is stored. Perhaps some of the confusion between the two options comes from people who are familiar with the flash file systems on Linux – YAFFS, JFFS2, and UBIFS. Here is how the Datalight solution is different.

Supporting a wide range of kernel versions

The Linux environment is full featured and modern, with updated kernels being released far more frequently than comparable environments such as Wind River’s VxWorks or Microsoft’s Windows Embedded. Among factors driving the choice of those kernels for an embedded design are features, flexibility, and kernel requirements among chosen software and hardware drivers.

How Sure Are You of Device Reliability?

For an embedded system, reliability means no unexpected loss of data. Looking below the application, this breaks down into two main categories:

Performance Drop Without Discards

While working on our Discards whitepaper and testing our new Smart Discards feature, we took a lot of performance measurements. One of these really stands out – but first a quick explanation.

Datalight's History with Discards

While working on a recent whitepaper, I dug up Datalight history for more info about discards. I’ve been with the company for over 16 years, and our work with discards predates not only my time on the job, but any other mention of discards for flash media.

Power Interruptions - The Enemy of NAND Flash Memory

On a recent call with a customer of ours, we were asked about reliability and power interruption. Specifically, the customer wanted to know why FlashFX Tera requires that page program operations not be interrupted, because he had conducted power interruption tests on eMMC and didn’t observe any failures.

The Capabilities of Scatter/Gather

Electronic Engineering Journal published an interesting article last week describing how scatter/gather works, to the limits of what could be said without NDA. This interesting technology doesn’t completely deliver on promises of single-cycle access, but does provide improved memory access speed.

Reliance Edge accessing media that requires a partition table

Reliance Edge is designed to handle very basic storage media. It doesn’t require any sort of partition table, and can utilize nearly the entire media. A minimal amount of overhead is required for the Reliance Edge Master Block and two Metaroots, and is placed at the beginning of the media. This can also be referred to as a partitionless disk or superfloppy. If that type of media won’t work in your software design, how can you make Reliance Edge work with media that requires a partition table?

Don’t Let a Potential Schedule Saver Become a Product Killer

More and more embedded devices are gaining the ability to connect – to each other, to private networks, and to the public cloud. This increasing connectivity is creating a fresh ease of delivering software updates to all kinds of devices that have been deployed to the field. While no one would argue that the ability to provide timely security updates is a bad thing, we need to be careful that this ubiquitous updatability doesn’t tempt us to ship a product before it’s really ready. And more importantly, that we plan for a failsafe way to manage updates when they do happen.

Explaining OverlayFS – What it Does and How it Works

Union file systems are a creative solution to allow a virtual merge of multiple folders, while keeping their actual contents separate. The Overlay file system (OverlayFS) is one example of these, though it is more of a mounting mechanism than a file system. Brought into the Linux kernel mainline with version 3.18, OverlayFS allows you to overlay the contents (both files and directories) of one directory onto another. The source directories can be on different volumes and can even be different file systems, which creates an interesting mechanism for allowing temporary modification of read-only files and folders.

Reliance Nitro Transaction Explorer

One of the key differentiators for Datalight's Reliance Nitro file system is the runtime flexibility. Not only does this file system provide more reliability options than any other file system on the market, they can all be changed on the fly through a simple API. To demonstrate just how easy this was, we created an intern project to do just that.

FlashFX Tera Feature Highlight: The Error Policy Manager

Datalight's FlashFX Tera is quite similar in structure to its predecessor, FlashFX Pro, but there have been some features that have evolved from our experience in working with NAND flash over the years that are reflected in some of the new features you will now find in our FlashFX Tera product, and the Error Policy Manager is one of them.

Comparing Two Protocols for USB Devices

The USB Mass Storage class (also called UMS) is a protocol that allows a device connected through USB (Universal Serial Bus) to become accessible to a host computing device. This allows file transfers between the device and the desktop, as long as the file system used on the device is known to the desktop. One common example of this is the FAT file system.

Why CRCs Are Important

Datalight's Reliance Nitro and journaling file systems,such as ext4, are designed to recover from unexpected power interruption. These kinds of "post mortem" recoveries typically consist of determining which files are in which states, and restoring them to the proper working state. Methods like these are fine for recovering from a power failure, but what about a media failure?

Write Amplification: The Next Device Optimization Battle?

Wikipedia describes Write Amplification as "an undesirable phenomenon associated with Flash memory and solid-state drives (SSDs) where the actual amount of physical information written is a multiple of logical amount intended to be written," and offers this formula to calculate it:

What is JEDEC, and how does it affect me?

EDEC, the Joint Electron Devices Engineering Council (see, is a group of manufacturers and suppliers collaborating to create specifications for Flash memory access and parts.

ONFI Announces EZ-NAND at FMS: OEMs Rejoice

Last week's Flash Memory Summit was a whirlwind of tutorials, announcements and networking, including a presentation by our very own CEO Roy Sherrill, but if you missed the announcement by ONFI (the Open NAND Flash Interface organization) that its new ONFI 2.3 specification will include the EZ-NAND protocol, take a few minutes to soak it in.

Psst! Datalight is the "secret sauce"

Customers tell us the performance and reliability benefits of our products are important competitive advantages for them. So with hundreds of Datalight customers shipping millions of products, why don't you see more glowing reviews and fact-driven case studies on our website? As one top-tier consumer OEM recently told us, "If our competitors know that we use Datalight, they may use it too, and we don't want to lose that advantage." What a fantastic endorsement - Datalight is aningredientof this customer's "secret sauce!" Just last week an OEM building a metering product expressed reluctance to have us publish a case study. They were concerned competitors googling their name would find it and learn about the problem Datalight solved for them. One the one hand, it's wonderful that our products are a factor in customers beating their competition; on the…