Re: Easy and fast way for Mac users to backup/restore their RPi SD card

Richard - VE7CVS

I set up some scripts (using dd and such) to make loading SD cards easy for a high school Physics teacher who uses Pis in her classroom.

Not too hard to use - but I'm going to move her to ApplePi-Baker (whenever school opens again)!

I'm going to use it too. Why not make things easy? I'll still use dd for some operations (I *am* an ornery old sysadmin :-), but a simple, GUI-based tool that includes compression/decompression is a great idea. Using dd plus gzip/bzip gets old after a few cycles.

I disagree slightly with item 3 - As long as the target card is larger than the original, you can put a smaller image on a larger SD card (at least with Raspbian images and cards up to 32GB). I did find, though, that if you put an image that is triggered to grow when it's booted, it will only grow to the size of the original card. So, a small, 4GB image that was built on an 8GB card and triggered to grow will only grow to 8GB, even on a 32GB card. I could probably fix that, but 8GB images were big enough for my target use.

It *is* possible to retrigger growth again to get up to 32GB, but that's a manual operation.

I'm downloading dcfldd too!

Thanks for the pointers, Basil!

- Richard, VE7CVS/W6

On 3/22/20 12:20 PM, Basil Gunn wrote:
Why using ApplePi-Baker V2 on a MAC or Drewsif/PiShrink on a Linux
machine is better than just using the 'dd' utility.

1. If you think managing a number of 16, 32 or 64GB images is easy then
you don't do it very often.

2. Using a utility that gets rid of most of the unused sectors in your
mSD card file system results in a significantly smaller image. Add some
compression on that image and now you have an image size that while
still large is at least reasonably manageable.

3. Both ApplePi-Baker V2(MAC) & Drewsif (Linux) provide an expand on
boot utility. What you will find is that unless your target mSD card has
exactly the same architecture (cylinders/heads/sectors) as your source
mSD card, using dd to write an image your mSD card will fail to
boot. Buying the same SD card as you last used a few months ago does NOT
guarantee that both cards have the same architecture.

4. The Department of Defense Computer Forensics Lab (DCFL) provides a
superior utility to dd called dcfldd (

/Basil n7nix

Charles Blackburn <> writes:

it's mach so it's *nix based. just use the DD command and be done with it...

eg: SD card is /dev/sdc

dd if=/dev/sdc of=MyPiSDCard.iso BS=2048

to write it back just swap the parameters around.


On 3/22/2020 1:29 PM, Brian K7BLS wrote:
For several weeks I’ve been fiddling with various schemes to backup and duplicate an RPi SD card using my Mac. I tried several approaches from websites using the Terminal and they were all slow and failed at some point.

Then I discovered ApplePi-Baker V2

Very easy to install on Mac from the website. Do follow the directions.

I created a backup of the SD card to Mac as .zip and compressed. Starting from a 16 GB SD card it took 18 minutes and only used 6.6 GB in storage.

Very easy to restore to another SD card and took 24 minutes.

THE RESTORED IMAGE WORKED ON THE RPi!!!! All controls from a GUI, not Terminal. You get to watch the progress on a dial with estimated time remaining and a detailed log.

Many thanks to Basil N7NIX and Clark K7LRK for support and encouragement.

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