The bit about SD cards being slow at random reads is interesting. Lately I've been mulling over an idea for Raspberry Pi-like computers, where you use an initramfs as your root FS, have some kind of process for rebuilding it with new packages, and only selectively write to the SD card the things that you really need to be durable. Haven't really fleshed it out yet, though.

@matt That's an interesting idea! Perhaps a base image on squashfs or something that gets copied to zram on boot, and then overlayfs/aufs/etc to capture changes above it. The problem there may be the limited RAM of the Pis though.

That's a valid point about limited RAM. Of course, there are Pis these days with more RAM, so depending on how big the root FS is, it might not be practically an issue. On early personal computers we used to load the OS and current application fully into RAM up-front, especially so we could swap the floppy in our one floppy drive.

Yeah, it's funny, on my family's first computer (an Apple IIGS), the thing I wanted most was a hard drive. And now I'm wanting to recreate the old experience of tinkering without worrying about wrecking the one OS install by switching between multiple bootable floppies, but now using SD cards.