Raspberry Pi requires no introduction. It is a small, affordable and credit-card sized computer that can be connected to a Monitor or TV. We can attach a standard keyboard and mouse and use it as a full-blown desktop computer to do everyday tasks, such Internet browsing, playing videos/games, word processing and spreadsheet making and a lot more. It has been mainly developed for teaching Computer science in schools. Nowadays, Raspberry Pi is widely being used in colleges, small-medium organizations and institutes to teach coding. If you own a Raspberry Pi device, you might want to check out a bash script named "PiShrink", which is used to make Raspberry Pi Images smaller.
PiShrink will automatically shrink a pi image that will then resize to the max size of the SD card on boot. This will make putting the image back onto the SD card faster and the shrunk images will compress better. This can be useful to fit the large size images in your SD card. In this brief guide, we are going to learn to shrink Raspberry images to smaller size in Linux and Unix-like systems.
Install PiShrink in Linux
To install PiShrink on your Linux box, first download the latest version using command:
$ wget https://raw.githubusercontent.com/Drewsif/PiShrink/master/pishrink.sh
Next, make the downloaded PiShrink binary as executable:
$ chmod +x pishrink.sh
Finally, move it your path:
$ sudo mv pishrink.sh /usr/local/bin/
Shrink Raspberry Pi Images Using PiShrink
As you may already know, Raspbian is the official operating system for all models of Raspberry Pi. The Raspberry foundation has developed Raspberry Pi Desktop version for PC and Mac. You can create a live cd, run it in virtual machine and even install it in your desktop as well. There are also few unofficial OS images available for Raspberry Pi. For the purpose of testing, I've downloaded the official Raspbian OS from the official download page.
Unzip the downloaded OS image:
$ unzip 2019-04-08-raspbian-stretch-lite.zip
The above command will extract contents of 2019-04-08-raspbian-stretch-lite.zip file in the current working directory.
Let check the actual size of the extracted file:
$ du -h 2019-04-08-raspbian-stretch-lite.img 1.7G 2019-04-08-raspbian-stretch-lite.img
As you can see, the size of the extracted Raspberry OS img file is 1.7G.
Now, shrink this file's size using PiShrink like below:
$ sudo pishrink.sh 2019-04-08-raspbian-stretch-lite.img
Creating new /etc/rc.local rootfs: 39795/107072 files (0.1% non-contiguous), 239386/428032 blocks resize2fs 1.45.0 (6-Mar-2019) resize2fs 1.45.0 (6-Mar-2019) Resizing the filesystem on /dev/loop1 to 280763 (4k) blocks. Begin pass 3 (max = 14) Scanning inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Begin pass 4 (max = 3728) Updating inode references XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX The filesystem on /dev/loop1 is now 280763 (4k) blocks long. Shrunk 2019-04-08-raspbian-stretch-lite.img from 1.7G to 1.2G
As you see in the above output, the size of the Rasberry Pi image has been reduced to 1.2G.
You can also use -s flag to skip the autoexpanding part of the process.
$ sudo pishrink.sh -s 2019-04-08-raspbian-stretch-lite.img newpi.img
This will create a copy of source img file (i.e 2019-04-08-raspbian-stretch-lite.img) into a new img file (newpi.img) and work on it. For more details, check the official GitHub page given at the end.
It TOTALLY AMAZES ME that after all this time there does not exist a simple utility that can create a properly sized Raspbian backup image!
pls remove my ps in my reply
i had forgotten to “sudo mv pishrink.sh /usr/local/bin/” :> so the script is even bether i just heve to learn reading 😉
SK, Thank You So much for your PiShrink script ! Works great, per your instructions !!!
Bravo SK, very useful script you made and shared with us. Thank you very much and make my life so much easy.
Is there a way (short of dd and then pishrink) to take the SD Card, and create a shrunk image that will expand on boot? I’m assuming that I’ll have to use dd and then pishrink the img file. But, I’m hoping there’s a built-in way to do it.
I have no idea how to do it exactly. I came across this guide after a quick google search. May be this might help. https://blog.dhampir.no/content/shrinking-a-raspbian-installation-and-re-enabling-auto-expanding-for-distribution-of-customized-images
Also try Raspberry pi stackexchange forum. https://raspberrypi.stackexchange.com/
The file system seems to expand automatically – at least in Raspios-Buster. I created an image where I’d done all the updates (which takes forever) Shrunk it down on a Pi from 16Gb to 4Gb then inserted into a Pi4 and booted up. It was slow first time around and at one point seemed to restart. I enabled VNC and had a look and the file system is reporting 10.1GB free out of as total of 13.9Gb.
That’s all I did folks.
Wow – HUGE thanks for this – can’t tell you how many times I have tried but failed to shrink an img – (clearly beyond my skill but a significant need) . Worked fantastic, just remember you need let it resize the file system to the new SD size, and reboot – for me a couple of times to complete. So helpful when you have an image file from one vendor card and try to re-image it to another vendor card that is of course, not the exact same size, and fails because it is too big to fit – great solition! I had a 32gb image, that it shrank to 4gb, which I then Win32 Disk Imager to a 16GB SD, upon boot up it then expanded to the new capacity and re-booted fine. Thanks Again