Duplicating Rasberry Pi Images

August 17th, 2022
jammer, tech
About a year ago I moved my rhythm stage setup over to run on a Raspberry Pi. I really like having a small light box that does just this one thing. Currently I have two of them, one for the whistle synth and one for everything else.

Because I wanted some insurance against failures at gigs, both boxes are configured identically, and decide which role to take on based on what inputs they receive. This means that if one of them fails I can use the other, for either bass whistling or midi silliness depending on which I need more.

When Kingfisher played our first dance weekend a month ago, this did happen. I think the SD card on one of the boxes was corrupted by a bad shutdown. Since I have extra SD cards, I decided to make some SD card clones.

On my Mac this looked like:

$ diskutil list
/dev/disk0 (internal):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                         500.3 GB   disk0
   1:             Apple_APFS_ISC                         524.3 MB   disk0s1
   2:                 Apple_APFS Container disk3         494.4 GB   disk0s2
   3:        Apple_APFS_Recovery                         5.4 GB     disk0s3

/dev/disk3 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +494.4 GB   disk3
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            15.4 GB    disk3s1
   2:              APFS Snapshot com.apple.os.update-... 15.4 GB    disk3s1s1
   3:                APFS Volume Preboot                 446.8 MB   disk3s2
   4:                APFS Volume Recovery                822.2 MB   disk3s3
   5:                APFS Volume Data                    251.1 GB   disk3s5
   6:                APFS Volume VM                      1.1 GB     disk3s6

/dev/disk4 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *31.3 GB    disk4
   1:             Windows_FAT_32 boot                    268.4 MB   disk4s1
   2:                      Linux                         31.0 GB    disk4s2

Seems like the SD card is /dev/disk4.

$ diskutil unmountDisk /dev/disk4
Unmount of all volumes on disk4 was successful
Best to unmount it before reading from it, and required before writing to it.

I made an image:

$ time sudo dd if=/dev/disk4 of=~/Desktop/rpi.dmg
61069312+0 records in
61069312+0 records out
31267487744 bytes transferred in 807.574215 secs (38717789 bytes/sec)

real        13m27.618s
user        0m12.921s
sys         4m47.337s

Swap the SD card for another, diskutil unmountDisk /dev/disk4 again, then write the image:

time sudo dd if=~/Desktop/rpi.dmg of=/dev/disk4
61069312+0 records in
61069312+0 records out
31267487744 bytes transferred in 4960.289760 secs (6303561 bytes/sec)

real        82m40.324s
user        0m16.477s
sys         3m51.574s

Pop the card out, put it in the Raspberry Pi, and it works!

I compressed the image to save for later:

$ cat ~/Desktop/rpi.dmg | gzip > ~/Desktop/rpi.dmg.gz
$ du -hs ~/Desktop/rpi.dmg*
 29G /Users/jeffkaufman/Desktop/rpi.dmg
1.0G /Users/jeffkaufman/Desktop/rpi.dmg.gz

Looking forward to playing Spark in the Dark a week from Saturday with a little more tech redundancy!

Referenced in:

Comment via: facebook, lesswrong, substack

Recent posts on blogs I like:

Effective altruism and PR

I. The “effective altruists should be more concerned about PR” brigade has been out in full force on X recently.

via Thing of Things October 8, 2026

There's no point at which turning your brain off will work

In early 2025, I started seeing people turn off their brain as they use LLMs1. They would have an LLM take an action (summarize text, write some code, etc.), and just assume that it worked2. This generally didn't work in early 2025 and the result was …

via Posts on September 18, 2026

My Weirdy Creatures

Over the last few days, I've been working on some little creatres. But they're very weird. I call them "weirdy creatures". I've made quite a lot of them, I think maybe 5-6, not sure. Weirdy Predator This is a weirdy predator. They'…

via Anna Wise's Blog Posts September 13, 2026

more     (via openring)