The backup file is copied to RAM but extensions are mounted by default.
In cloud mode, extensions are downloaded to RAM and then mounted (they are gone after reboot).
I thought I read that cloud mode was the default. How do I know what mode I am in?
If you have persistent storage for extensions, mounted extensions don't consume RAM except for several KB for the mount point.
That sounds like what I want.
Why use piCore if you don't want an small embedded Linux in RAM?
I DO want small, tightly-wound, highly-reliable, embedded Linux. And in particular, I want it to boot as fast as possible. I don't really care if the entire OS is in RAM except that: 1) copying the entire OS to RAM would undoubtably slow down the boot process and 2) it will waste RAM, which is scare on the PiZero to begin with.
BTW, I'll also need to store my app data (photos) directly to SD. Any reason I should create a 3rd partition vs. just creating a data directory on /mnt/mmc0blk0p2?