Alert admin when sd card lacks enough space

[Halloran]

Description
Provide admin account with alerts when the free space available on the sd card (or perhaps root fs) gets very low

Example
If you image the latest nextcloudpi (1.54.2) to a 16mb SD Card, you will be able to boot the system but it operates painfully slowly and when you fill it further, fs errors will start occurring but are not easily diagnosable as being caused by the lack of space. Perhaps there is a way to alert the admin account, as some other events are sent to the admin via email (password resets, etc).

[theCalcaholic]

good suggestion, I'll keep it in mind :)