How to resize a Gokrazy SD card

Published on , 953 words, 4 minutes to read

An image of 1girl, green hair, green eyes, tshirt, jeans, sneakers, seattle, space needle, controlnet overlay: soyjacks pointing
1girl, green hair, green eyes, tshirt, jeans, sneakers, seattle, space needle, controlnet overlay: soyjacks pointing - Anything V3

I have a Raspberry Pi embedded into my main shellbox. This allows me to have a built-in device that lets me do things like act as a serial terminal of last resort for my tower. It's powered by a Molex to USB-A cable (which is about the most cursed cable I have ever used) and probably benefits from the absolutely overkill tier Noctua cooler that I put on that board.

A picture of pneuma, my main shellbox node, with a Raspi 4B shown placed on top of a paper towel to shield from shorts against the aluminum frame of the case.
A picture of pneuma, my main shellbox node, with a Raspi 4B shown placed on top of a paper towel to shield from shorts against the aluminum frame of the case.

Recently I decided to put GoToSocial on that Raspberry Pi to see if it would work in Gokrazy. Turns out it does! I also installed minio on there to act as an S3 compatible storage solution and it's basically a little social network in a box.

Mara is hacker
<Mara>

This will be discussed in greater detail in a future post.

However, there was only one problem. I set up my Gokrazy node with a 64 GB SD card because that's what I had laying around. Given that social media stuff can take a lot of data, I wanted to upgrade it to a 512 GB SD card so that I didn't have to care about it for a while. I also wanted to make a backup of the XeDN bucket onto the Raspi as well as another one I'd mail to a friend.

Here's how I copied the data over to the new SD card.

First, I plugged both SD cards into my shellbox over the front panel USB. My SD card reader had support for both a Micro SD card and a normal SD card, so I plugged the 64 GB card into a SD-uSD adaptor and had both of them connected. If you only have one SD card slot to play with, you can also copy the data to a file as an intermediate step.

Once they were plugged in (the old one was chosen to be /dev/sde and the new one was chosen to be /dev/sdd), I copied the data over with dd(1):

sudo dd if=/dev/sde of=/dev/sdd bs=4M status=progress
Mara is hacker
<Mara>

In dd, the if= is the input file and the of= is the output file. These can be any files you want, even normal files on the disk. If you SD card reader doesn't have two slots, you will have to set the output file to somewhere on the disk, and then use that file as the input file for the next run. It'd be something like:

sudo dd if=/dev/sde of=./sdcard.img bs=4M status=progress
(swap cards)
sudo dd if=./sdcard.img of=/dev/sde bs=4M status=progress

Keep in mind that when you're running dd commands like this, you are basically working without guardrails or handbrakes. You need to be absolutely certain that you are dealing with the correct devices. You can check these by using the lsblk or dmesg commands.

lsblk lets you see the storage "block" devices that are connected to a Linux machine. For example, here's what you could see on a Linux machine's NVME drive:

$ lsblk /dev/nvme0n1
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
nvme0n1     259:0    0 931.5G  0 disk
├─nvme0n1p1 259:1    0   923G  0 part
├─nvme0n1p2 259:2    0     8G  0 part [SWAP]
└─nvme0n1p3 259:3    0   511M  0 part /boot

dmesg lets you see the kernel log buffer. You may want to run it with -w so that you can continuously watch the changes. When figuring out which SD card was which, I used dmesg -w to look for new block storage devices being connected, and then lsblk to figure out which one was the old/new one. Gokrazy sets up 4 partitions (boot, root A, root B, and persistent storage), so you can also use that to help you figure out which is which.

The data copy took at least half an hour, which I left running while playing some Pokemon Infinite Fusion.

Once it was done, I ran the sync command for good measure and disconnected my SD card reader. Then I removed the old SD card and plugged the reader back in. After running the lsblk command, I knew I was good.

Now I needed to resize the partition at /dev/sdd4. I installed growpart from the cloud-utils package and ran it on the SD card:

sudo growpart /dev/sdd 4

This grew the GPT tables for the SD card to fit the new size. Next I needed to run a filesystem check on the storage partition and resize it with resize2fs:

sudo e2fsck -f /dev/sdd4
sudo resize2fs /dev/sdd4

After that finished, I test-mounted the storage drive on /mnt/aile and unmounted it. Everything worked great. I took out the SD card from my shellbox, popped the new card into the raspi, booted it up and bam: 512 GB of storage:

A picture of the Gokrazy web UI, showing the fact that the pi has about 450 GB of storage available. It would be 500-ish, but disks are labeled in base 2 bytes and computers usually display things in base 10 bytes. I hate it too.
A picture of the Gokrazy web UI, showing the fact that the pi has about 450 GB of storage available. It would be 500-ish, but disks are labeled in base 2 bytes and computers usually display things in base 10 bytes. I hate it too.

Stay tuned, I have plans.

Facts and circumstances may have changed since publication. Please contact me before jumping to conclusions if something seems wrong or unclear.

Tags: gokrazy