Lower the threshold for Low Disk Space warning in Ubuntu

The Low Disk Space warning in Ubuntu is set at 95% and minimum 1 GB free space, which can sometimes be too late if space is running out.

If you would like to get a warning earlier, and more time to clear up space before everything crashes, open dconf and set these values:

/org/gnome/settings-daemon/plugins/housekeeping/free-percent-notify

"Free percentage notify threshold
Percentage free space threshold for initial warning of low disk space. If the percentage free space drops below this, a warning will be shown."

Decrease from 95% to for example 85%.

/org/gnome/settings-daemon/plugins/housekeeping/free-size-gb-no-notify

"Free space notify threshold
Specify an amount in GB. If the amount of free space is more than this, no warning will be shown."

Increase from 1 GB to for example 30 GB.