PiShrink

PiShrink is a bash script that 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. In addition the shrinked image can be compressed with gzip, pigz, xz or pxz to create an even smaller image.

Usage

sudo pishrink.sh [-sdirzh] imagefile.img [newimagefile.img]
  -s         Don't expand filesystem when image is booted the first time
  -d         Write debug messages in a debug log file
  -r         Use advanced filesystem repair option if the normal one fails
  -p         Remove logs, apt archives, dhcp leases and ssh hostkeys
  -v		 Be verbose
  -z         Compress image after shrinking
  -i TOOL    Zip tool to use to compress image. TOOLS can be one of $ZIPTOOLS (Default: gzip)
  -a         Use parallel compress feature of compression tool

If you specify the newimagefile.img parameter, the script will make a copy of imagefile.img and work off that. You will need enough space to make a full copy of the image to use that option.

• -s will skip the autoexpanding part of the process.
• -d will create a logfile pishrink.log which may help for problem analysis.
• -r will attempt to repair the filesystem if regular repairs fail
• -z will compress the image after shrinking using gzip or xz. Default is gzip. .gz or .xz extension will be added to the filename.
• -a will use option -f9 for gzip and option -T0 for xz.

Default options for parallel compression can be overwritten by defining PISHRINK_GZIP or PSHRINK_XZ environment variable.

Prerequisites

If you are trying to shrink a NOOBS image it will likely fail. This is due to NOOBS partitioning being significantly different than Raspbian's. Hopefully PiShrink will be able to support NOOBS in the near future.

If using Ubuntu, you will likely see an error about e2fsck being out of date and metadata_csum. The simplest fix for this is to use Ubuntu 16.10 and up, as it will save you a lot of hassle in the long run.

Installation

wget https://raw.githubusercontent.com/Drewsif/PiShrink/master/pishrink.sh
chmod +x pishrink.sh
sudo mv pishrink.sh /usr/local/bin

Example

[user@localhost PiShrink]$ sudo pishrink.sh pi.img
e2fsck 1.42.9 (28-Dec-2013)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/loop1: 88262/1929536 files (0.2% non-contiguous), 842728/7717632 blocks
resize2fs 1.42.9 (28-Dec-2013)
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/loop1 to 773603 (4k) blocks.
Begin pass 2 (max = 100387)
Relocating blocks             XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 3 (max = 236)
Scanning inode table          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 4 (max = 7348)
Updating inode references     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/loop1 is now 773603 blocks long.

Shrunk pi.img from 30G to 3.1G

Contributing

If you find a bug please create an issue for it. If you would like a new feature added, you can create an issue for it but I can't promise that I will get to it.

Pull requests for new features and bug fixes are more than welcome!