Backup from one card to another

In the interest of making my Little Backup Box kit even smaller, i would like to backup my SD cards to a Micro SD card (instead of using a USB flash drive).

In order to ensure that the backup script reads from, and writes to, the correct cards: I assume I should plug in the card reader – with the the designated target card (Micro SD) already in it – into the Raspberry Pi, then put the designated source card (SD) into the card reader…

Will this work as planned?

Is there a compelling reason not to do it?

So you want to use a card reader with a microSD card in it and a backup device? Then the procedure is correct: first, insert the backup (destination) device, then insert the source card.

Another alternative is to use the internal system card as a backup destination. This will reduce the size of your Little Backup Kit even further. In this case, you need to use the internal backup script.

Kind regards,

Yes – I want to use two cards in the same card reader. An SD card as the source and a micro SD card as the destination. I tested it out, and it seems to work OK as long as I put the destination card into the card reader first, then wait a few seconds, then put the source card into the same card reader.

Regarding using the internal system card as the backup destination: I have not been able to get that to work. The light on the card reader blinks, then the Raspberry Pi shuts down, then I put the system micro SD card into a card reader to view the contents on my Mac… and there is no folder of image files (just the regular Raspbian Lite system files).

While I’m at it… The card I’m using for my Raspbian system is a 16 Gig card. I formatted it on a Mac with the “SD Card Formatter” app, then I flashed the Raspbian Lite image to it using BalenaEtcher. When I mount the card on a Mac and look at it in Disk Utility, it shows up as having two volumes – a 268.4 MB volume (with 208.8 MB free), and an unnamed 15.66 GB volume that I can’t access at all on my Mac.

What happened to all my space???

p.s. I am fairly competent with a Mac, but I know almost nothing about Linux.

No, no, no! You cannot use two cards in the same card reader.

Hmm, I need to try this myself.

That’s correct. Flashing the image creates two partitions on the card: boot and root

Whoops! Good thing I clarified that.

FWIW, it does seem to work – as long as the cards are put into the card reader in the right order.

I can only see the “boot” partition on my Mac. How do i access the “root” partition? maybe the internal backup is somewhere in there…

Would two cards inserted in to a reader with multiple slots not be assigned different /dev/sdXY variables? or does the code require X to be different too?

1 Like