> For the complete documentation index, see [llms.txt](https://campus-rover.gitbook.io/lab-notebook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://campus-rover.gitbook.io/lab-notebook/fiiva/copy_microsd.md). # How to Copy a MicroSD * Current best resource on web: [The fastest way to clone an SD card on macOS](https://blog.jaimyn.dev/the-fastest-way-to-clone-sd-card-macos/) ## Identify your sd card You’ll need to find out which disk your SD card represents. You can run `diskutil list` and should see an output like below: ``` $ diskutil list /dev/disk1 (synthesized): #: TYPE NAME SIZE IDENTIFIER 0: APFS Container Scheme - +500.0 GB disk1 Physical Store disk0s2 1: APFS Volume Macintosh HD — Data 396.0 GB disk1s1 2: APFS Volume Preboot 81.9 MB disk1s2 3: APFS Volume Recovery 528.5 MB disk1s3 4: APFS Volume VM 4.3 GB disk1s4 5: APFS Volume Macintosh HD 11.0 GB disk1s5 /dev/disk4 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *31.9 GB disk4 1: Windows_FAT_32 boot 268.4 MB disk4s1 2: Linux 31.6 GB disk4s2 ``` From that output we can see that our SD card must be `/dev/disk4` as our card is 32GB in size and has a fat32 and linux partition (standard for most raspberry pi images). You should add an r in front of disk4 so it looks like this `/dev/rdisk4`. The r means when we’re copying, it will use the “raw” disk. For an operation like this, it is much more efficient. ## Copy the SD card as a disk image (dmg) Now you should run the following command, replacing 4 with whatever number you identified as your sd card: `sudo gdd if=/dev/rdisk4 of=sd_backup.dmg status=progress bs=16M` Tip: you can experiment with different numbers for the block size by replacing bs=16M with larger or smaller numbers to see if it makes a difference to the speed. I’ve found 16M the best for my hardware. You should see some progress feedback telling you the transfer speed. If you’d like to experiment with different block sizes, just type ctrl + c to cancel the command, then you can run it again. Once the command has finished running, you’ll end up with a file in your home directory called sd\_backup.dmg. If you’d like to backup multiple SD cards (or keep multiple backups!) simply replace sd\_backup.dmg with a different file name. This will contain a complete disk image of your SD card. If you’d like to restore it, or clone it to another SD card, read on. ## Copy the disk image (dmg) to your SD card You’ll first need to unmount your SD card. Do not click the eject button in finder, but run this command, replacing 4 with whatever number you identified as your sd card `sudo diskutil unmountDisk /dev/disk4` Then to copy the image, run the following command: `sudo gdd of=/dev/rdisk4 if=sd_backup.dmg status=progress bs=16M` Tip: you can experiment with different numbers for the block size by replacing bs=16M with larger or smaller numbers to see if it makes a difference to the speed. I’ve found 16M the best for my hardware. You should see some progress feedback telling you the transfer speed. If you’d like to experiment with different block sizes, just type ctrl + c to cancel the command, then you can run it again. Once the command has finished running, your SD card should be an exact copy of the disk image you specified. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://campus-rover.gitbook.io/lab-notebook/fiiva/copy_microsd.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.