Flash Wear

A warning note tonight. Flash memory wears out. And fails.

We are prepared to pay premium price for the latest and greatest SSD drives that lift performance of our systems to then next level. While the performance side is true indeed, we have to face one serious risk: flash (solid state) memory is generally not safe. At some point in time my SSD drive will refuse to write data. But this will probably be caught by the operating system (at least this is what I hope...). Or worse - it will silently lose stored data and will refuse to read it. This is a relatively high risk.

Why do I write about this? Because I have just had a really bad week, with four devices that failed due to flash wear problem. The first was the Toshiba Network Camera. It simply refused to store new configuration changes and went dead after I tried to upgrade its firmware. The second was the accompanying NSLU-2 based little FTP server. It rebooted one day and reported there were no USB drives connected to it (well... there was a pen drive in the slot, but it lost all the data, including partition tables). Next was the Kathrein UFS-910 satellite set-top-box receiver. I was running a routine configuration update on it and it never started again. A connected debug console was showing "Flash CRC error", so it went back to the factory for a repair. And last Friday my backup Dling DFL-800 router / firewall refused to start after a power glitch, again a console connected to monitor the RedBoot loader was showing Flash CRC error....

And this all happened just exactly the week when I installed the new Toshiba SSD drive in my primary Lenovo X200s system. The SSD works great so far, but as my college teacher used to say "memento mori". I am doing full mirror backups earlier than usual. Despite the price, the SSD comes with just one year warranty, instead of three years most mechanical drives come with today.

Well... all these events may be just a bad luck... but no... flash - based solid state storage is not safer than mechanical spinning drives today. Somehow contrary to what most of us would expect. This will likely improve in future... but so far... make backups :)