fruitoftheloom suggested using SD Card Copier "to back up to another SD Card in a USB SDHC Card Reader". It only runs in the GUI version of Raspbian.pi-anazazi wrote: ... unbelievable thread here. As fruity pointed out in the very beginning: Use piclone, it resized to whichever size you want. In just 5 minutes you're done.
piclone appears to be the command line version of SD Card Copier... https://github.com/raspberrypi-ui/piclo ... src/backup piclone doesn't "resize(d) to whichever size you want". It clones a running SD card onto another SD card. The resulting size of the clone is determined by the size of the destination disk which it occupies the entirety of and you have no choice over that.
Neither satisfy my use case, which I made clear from the start, I am using headless Raspbian and my goal is to create a backup image file, in which the size of the image file is minimized with regard to how much space is occupied by the root file system. I will store these backups on a drive somewhere along with several others and optionally flash them to an SD card at some future point in time.