On Thu, 9 Jul 2020 at 17:27, Alistair Francis <alistai...@gmail.com> wrote: > > On Thu, Jul 9, 2020 at 7:35 AM Philippe Mathieu-Daudé <f4...@amsat.org> wrote: > > > > On 7/9/20 4:15 PM, Peter Maydell wrote: > > > The only chance you have of something that's actually > > > generic would probably involve "qemu-img resize". But I'm a bit > > > wary of having an error message that recommends that, because > > > what if we got it wrong? > > > > I am not sure what to recommend then. > > > > Would that work as hint? > > > > qemu-system-arm -M raspi2 -sd ./buster-lite-armhf.img > > qemu-system-arm: Invalid SD card size: 1.73 GiB > > SD card size has to be a power of 2, e.g. 2GiB. > > That sounds good to me. That's enough for a user to figure out the next step. > > If you want you could also add: "qemu-img might be able to help." or > something like that.
Thinking about it a bit and talking to Philippe on IRC, I think we can usefully have the message recommend "qemu-img resize" to the user; I think we should avoid printing out an exact-cut-n-paste command line just in case it's wrong, but something like: qemu-system-arm: Invalid SD card size: 1.73 GiB SD card size has to be a power of 2, e.g. 2GiB. You can resize disk images with 'qemu-img resize <imagefile> <new-size>' (note that this will lose data if you make the image smaller than it currently is) I think is a reasonable balance between pointing the user in the right direction and cautioning them to check what they're doing before they blithely perform the resize... thanks -- PMM