Duplicating Pi SD cards with etcher - invalid image?

I need to duplicate a number of SD cards from an existing card i create an image from command line using dd command to make a .dmg file. When i present this to etcher as a source image it gives me
"something went wrong while opening TMcardabckup.dmg
Error: invalid Image"

any suggestions on a good procedure how to clone a card using etcher?

Hey, the problem appears to the filename extension – if you’ve created a copy with dd, then that’s a flat binary copy of the device you’re cloning, and would best be labeled as .img, because .dmg are actually a specific file format which Etcher supports (hence the invalid image error).

So, renaming your TMcardabckup.dmg to TMcardabckup.img should do the trick, and get that working.

Hey Jonas !

Thanks so much for the advice, that’s making dupes with no problem now…



it seems i can run multiple copies of etcher writing to multiple SD readers from a single image - any reason not to?

There should be no downside to that.