Add a disk space default alert

[aieri]

Enhancement Proposal

Disk space metrics could be leveraged for alerting when disk space is too low.
Our current nagios-based solution uses the following default thresholds, which could be used as a starting point:

• warn if less than 25% of space is available
• critical alert if less than 20% of space or 5% of inodes are left

Obviously, prometheus metrics also give us a chance to create more sophisticated rules that include trends, e.g. "alert me if I'm going to run out of space in the next n hours".

[simskij]

Very good suggestion! Thanks @aieri!

[simskij]

Already resolved. Closing