Can you just duplicate the card and use that image as a backup? I’ve stashed a few away like this but pcdoodle’s suggested solution sounds a lot more elegant.

This is actually more difficult than you’d expect in some ways. The vast majority of card cloning guides will advise you to use the ‘dd’ command line utility, which makes an exact replica of the card, including the free space.

Unfortunately not all SD cards, even if advertised as the same capacity, are exactly the same size. If your replacement card is just 1 byte smaller your dd clone won’t restore - the “free” space has to fit into the target card as well.

Long story short - most popular methods of cloning microSD cards for the Pi only ensure the ability to restore to a larger SD card, not necessarily one of the same advertized size.

For sure there are workarounds, but it’s not as straightforward as you might assume. Personally I’m much more a fan of other tools such as rsync or version control etc for cloning data to and from Pi projects.

The better answer is just to USB boot the Pi anyway - they’ve supported this for a while now, no card corruption issues to mitigate.

Thanks for this. I need to change what I’m doing.

rsyncing the entire root file tree should be good enough.

Clonezilla?

Read only file system guides are out there. This makes it 90% more reliable.