I have an Anbernic RG350, a very nice hand-held gaming console: https://retrogame300.com/products/rg350 It uses a Linux distro that was developed for an older hand-held game console. It turns out that the OS and "internal storage" are on an actual microSD card inside the case: four screws and a gentle tug to get the card out, and you can image the "main drive." It's a 16G SD card with two partitions that occupy the whole card. Between them, they have 1.4G of used space. I imaged the whole card: # time dd if=/dev/sdi bs=4M of=./RG350.SD.2020-05-14.img conv=fsync status=progress This produced a roughly 16G image as expected. Then I compressed it: # time xz --threads=5 RG350.SD.2020-05-14.img This produced a 10G image. My assumption was that compression would see the empty partition space, presumably as a bunch of zeroes, and compress the crap out of it so that the final image would be the same size or smaller than the 1.4G of used space. I'm aware that the free space may not be zeroed out ... It's not encrypted, so that's not the issue. Is there a sane way to back this up that would produce a smaller image? I prefer to image the whole card ... and I like 'dd' because I'm familiar with it, although maybe I should move on ... Is somehow zeroing the empty space on the card a possibility? Suggestions welcomed ... I can live with the 10G backup if I have to, but would prefer a "better" solution if it's available. -- Giles https://www.gilesorr.com/ gilesorr@gmail.com