If you’ve noticed the numerous posts lately on the Datalight blog regarding JEDEC and eMMC, you might be wondering why we’re so excited about this particular standard. There are many features that this “smarter” memory will enable for OEMs; In this post I’ll focus on one of those features in the eMMC specification –secure delete.
Securely deleting information on flash memory is more complicated than it seems. For one thing, files are constantly being moved around to ensure even wear of the flash, resulting in multiple copies of file data on the media. Furthermore, when a file is marked for delete, it is typically not physically deleted, rather the space is only marked as available to be overwritten. Until that happens, the “deleted” data is still present and recoverable on the media. In fact, the University of California San Diego Non-volatile systems lab has produced an in depth study of file deletion on flash memory, where they found significant data still present on the media even after deleting the files. A copy of the report can be found at: http://cseweb.ucsd.edu/users/swanson/papers/Fast2011SecErase.pdf
In order to securely delete a file on raw flash, you must use a controller that will either track every block where the file has been stored, or will overwrite the space the file was stored in each time it is moved. The latter describes exactly the secure erase and secure trim features found in the eMMC 4.41 standard. This means that the hardware will finally be capable of securely deleting files –brilliant! There is just one problem: Who has software to support this functionality? As of this writing, there is no file system which supports the feature. While an application can make a call to the media to delete a file securely, the file system may have a backup copy stored somewhere. Fact is, the file system must support the secure delete capabilities of the hardware in order for these features to function correctly.
If an OEM wants to take advantage of the secure erase and secure trim features, their application will need to communicate with the eMMC driver, which may differ from part to part. As the only software company that is an active member of JEDEC, we are excited offer support for quite a few eMMC features. File system support for secure erase and secure trim will be coming later this summer!
Michele Pike | June 29, 2011 | Flash File System, Reliability |
That cracking you may or may not have heard last month was the sound of SanDisk and Toshiba breaking the sub-20 nanometer NAND barrier. Flying in the face of conventional wisdom (and more than a few industry analysts), both companies recently announced they will be delivering 19nm NAND this year. Intel and Micron are close behind, each with their own 20 nanometer announcements. Those who said it couldn’t (or shouldn’t) be done had some very compelling reasons, chiefly that the physics behind multi-cell architecture in a 1x nanometer cell are shaky at best. How many electrons will there be in a 1x nanometer cell? How many levels of data can possibly be detected with so few of them? The supporting technologies for this detection, not to mention correction of the unavoidable errors that will creep in will be critical .
In an industry that has come to expect product innovation in the form of shrinking die sizes being announced roughly every 12-18 months, keeping pace with this trend indefinitely is not only pushing the boundaries of physics, but also manufacturers’ technical abilities. How low can they go? While the introduction of 19nm parts show that innovation and scaling of NAND Flash memory continues moving at breakneck speed, one wonders when the end point of this shrinkage will finally come. And while the drive for NAND innovation has dramatically improved both the cost and performance of the technology, moving to ever smaller die sizes is beginning to have severe consequences on data storage reliability and flash endurance – challenges which must be addressed not only by the supporting hardware technologies but also by the file system and flash management software. Bottom line: Will the devices you’re responsible for provide the performance, life span and flexibility your customers require? What contingencies should you be planning for as the storage technologies get ever smaller?
RoySherrill | June 27, 2011 | Flash Memory Manager, Uncategorized |
Today we released our newest version of RWD (Reliance Windows Driver) with support for Windows 7. This is very good news for manufacturers and users of devices that need exchangeability with a Windows desktop, but can’t or won’t compromise performance and reliability to get it. As Windows 7 is enjoying much stronger adoption than Vista, we anticipate strong demand for RWD as well (it also supports XP and Vista). Check out the official press release for more details on this new version of RWD.
Michele Pike | October 28, 2010 | Flash File System, Flash Industry Info |
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. The news about EZ-NAND, which stands for error correction code (ECC) Zero NAND, is especially welcome for manufacturers of smart phones and other high-performance, price-competitive embedded devices. The EZ-NAND protocol dictates that ECCs are done by the NAND itself rather than by the NAND controller or device driver, a much more efficient method (as we’ve been blogging for nearly two years now). Also, in this era of fast-changing ECC NAND requirements, not having to keep up with the rapidly changing NAND ECC requirements by using costly high-end NAND controllers is a major competitive advantage for OEMs.
In current raw NAND implementations, the host controller is responsible for managing ECC and all other NAND functions like wear leveling, bad block management and compaction. ECC is notoriously difficult to implement in software, and EZ-NAND decouples it from the rest of these functions, allowing device designers to use the system processor for these functions and avoid the use of expensive NAND controllers. This setup, combined with a high-performance flash manager like FlashFX Tera, offers OEMs the ultimate combination of performance, flexibility and low cost to make those high-octane smart phone processors (MIPS, PowerPC, iMX-31 and OMAP families, etc.) really shine. While eMMC, with its hardware-based ECC seems to offer good compromise, the reality is that the other NAND functions (wear-leveling, bad block management and compaction) have to contend with the inexpensive controller found in the eMMC device. Translation: less-than-optimal use of the flash and seriously bogged-down performance in many use cases.
We would love to hear what you thought of this year’s Flash Memory Summit, what you learned, what surprised you and what you liked or didn’t like. Also, let us know if you have comments or questions about EZ-NAND using the comment field below.
Michele Pike | August 27, 2010 | Flash Industry Info, Flash Memory Manager |
Earlier this month (June 4th) SpaceX sent the Falcon 9 rocket on its maiden voyage from Cape Canaveral Air Force Station with a successful orbital insertion. Falcon 9 is a reusable spacecraft which will be used to resupply the International Space Station under the Commercial Orbital Transportation Services (COTS) program. We are delighted that SpaceX selected Datalight Reliance and FlashFX Pro to protect mission-critical data from the rigors of space travel, such as shock, vibration, temperature extremes and radiation. Emily Shanklin,Director, Marketing and Communications for SpaceX had this to say: “Datalight software enables reliable flash-based embedded computing for SpaceX’s upcoming Falcon 9 and Dragon spacecraft missions in the data-hostile conditions of space.”
Michele Pike | June 23, 2010 | Flash File System, Flash Memory Manager, Military/Aerospace, Reliability |
Bothell, WA, – June 15, 2010 – Today Datalight announced support for Micron Technology’s 4-gigabit (Gb) 34-nanometer (nm) NAND flash with on-die error correction code (ECC) within its popular flash managers, including FlashFX Pro and FlashFX Tera.
Read the full story here: http://bit.ly/9xn2DW
Michele Pike | June 16, 2010 | Flash Industry Info, Flash Memory Manager |
We just announced support for Linux Kernel Version 2.6.34. Read the full announcement here: http://bit.ly/c3UqXk
Michele Pike | June 9, 2010 | Flash File System |
Blackboard is the standard-bearer for student ID systems around the world. Their contactless cards serve as campus ID, building access, and point-of-sale accounts for meals and other services, and are rapidly replacing the old magnetic stripe systems. The cards and readers use a Windows Embedded CE-based platform. When Blackboard’s BSP provider learned that the systems would be responsible for keeping track of sensitive financial transactions, they recommended Datalight software to make certain that the system will function with bullet-proof reliability. To read more about our work with Blackboard, check out the full success story.
Michele Pike | May 20, 2010 | Consumer Other, Flash File System, Reliability |
Recently we developed a sample project to demonstrate how to boot Linux from flash on an embedded system. Booting NAND with a single (root) file system can be a challenge, even when using a NOR chip to initialize as this project did. So how did we do it? In order to simplify the process, we loaded our Datalight bootloader into the NOR flash and programmed the monitor that comes with the board to jump directly to it. So if you use the sample project with a Freescale i.MX31, a single command starts the loader and allows it to load the kernel and the initial RAM disk from flash managed by FlashFX Tera with Reliance Nitro. It will then read them into memory, jump to the kernel, and the kernel will start running code from the initial RAM disk which loads the FlashFX Tera and Reliance Nitro drivers into the kernel. Next, it mounts the flash as the root file system and the system is powered up and running. Within about ten seconds your i.MX31 is up and running with FlashFX Tera running the flash and Reliance Nitro running as the root file system. If you’d like to try it for yourself, we’ve included sample code for this project with our latest product release. In addition, our sample loader could just as easily be loaded into memory other ways.
Michele Pike | May 10, 2010 | Flash File System, Flash Memory Manager |