Resize Partition on Plan9
make sure to backup your partition / data in case something goes wrong
When I wrote the 9front image onto my sdcard it made one partition for booting and one with the operating system which was only about 1.7 gb. Which was not using the entire sdcard space. I could not find documentation on how to resize this partition, but figured it out.
I started the inst/main application and used the prepdisk tool. This has to be done in a terminal case and not through the cpu case.
I then deleted the partition which was called 'fs' and made a new partition with the same name, starting at the same sector, but ending at the end of the partition, the last sector available.
Delete the fs partition
Make the partition with the new size:
a fs [start sector] [end sector]
The system than stopped working, since I modified it while the system was running and after unplugging and plugging my pi, it successfully booted into the partition with the new size.