The factory image of IGT-20/ IGT-21 is less than 1GB, and however, the capacity of the default microSD is actually much larger. Though it’s a good idea to create a separated partition for user data, sometimes it’ll be an big issue if certain large software package, such as Node-RED, has to be installed. Here are some steps to expand the existing partition to the maximal capacity of the microSD.

wget https://raw.githubusercontent.com/iiot-tw/igt-20-utils/master/grow_partition.sh
wget -O /neousys/generic-startup.sh https://raw.githubusercontent.com/iiot-tw/igt-20-utils/master/neousys/generic-startup.sh
chmod +x grow_partition.sh
./grow_partition.sh
reboot

[updated: 31th Jan 2020]

This approach doesn’t apply to IGT-30 series, including IGT-30D, IGT-31D, IGT-33V, IGT-34C, for IGT-30 series has different partitions in the factory OS images.