Posted by mbohlmann on Feb 28, 2016; 1:02am
URL: https://itus.accessinnov.com/How-long-will-the-eMMC-flash-memory-last-on-our-shields-tp23p195.html

user8446,

Possible answer to your question: "...I have no idea if the controller on the shield has wear leveling or not..."

The Wikipedia entry for OpenWrt says this about the file system:

"A writable root file system, enabling users to add, remove or modify any file. This is accomplished by using overlayfs[23] to overlay[24] a read-only compressed SquashFS file system with a writable JFFS2 file system in a copy-on-write fashion. JFFS2 supports flash wear leveling."

https://en.wikipedia.org/wiki/OpenWrt