Guru
Joined: 05/03/2018
Location: NetherlandsPosts: 4723
| Posted: 10:38am 24 Jan 2025 |
John,
I was told that the eMMC controller (when powered) swipes the memory for errors, and when there are, it relocates and corrects (the error correction can correct X bit errors in each block). But over time, more bits fail (charge leaks away) and the block content is lost.
It is depending on your filesystem how you handle that. The filesystem can only see the block is flagged "corrupt". If this is part of your executable binaries, it should mark the whole file (multiple blocks) lost. And probably it will do that for the other file formats also. But in case it is a JPEG or MPEG file, recovery/repair could still be a valid option (family photo's). But I am not sure how a filsystem handles that, and if recovery is an option. It all depends on what is lost.
So in essence: I don't know.
Volhout
The horrid is that the number on this scary. When you have amodern high capacity eMMC/SD card, and write data and storage at 50+ degrees C (depending the temp rating of the card), 300 hours without power is sufficient for bit fails, and after 1000 hours it is not guaranteed they can be recovered. In 99.9% of cases they still can, but no guarantee is given anymore. For mission critical applications that is the number to work with. That is only 40 days ....
Temperature is major in this. At 25 degrees the numbers are far, far more friendly.
But storing family photos on SD card for years in the attic, where in summer it can reach 50C easily, may not be a good idea.
Edited 2025-01-24 20:43 by Volhout