@RonR,image-backup uses resize2fs to shrink the ROOT filesystem to the smallest size possible. The exact amount of free space remaining can vary. "Added space for incremental updates after shrinking" is then added to the resulting partition size.
Just to follow up, switching to the latest (2023-12-05) arm64 image seems to have solved the issue. Well, solved may be too ambitious - perhaps helped may better describe it. I used the same SD card and the same procedure to create a custom image and I am showing 357 MB free (using the +100 MB option). Better than 0. But using the Lite arm64 image as a base (on a Pi3b) and my final image has 1.2 GB free after shrinking. Not very efficient.
I don't understand why resize2fs has so much difficulty.
Statistics: Posted by RandyR — Sat Dec 09, 2023 8:24 pm