What happens if I decrease this value? Will it over time free up space as it can’t take new data and data may be deleted or will something very bad happen?
You can change it but it’s not just gonna start making space.
You still have to wait till those files are deleted.
And no nothing bad will happen, Unless you over allocate the space and end up corrupting’s the data bases.
I lowered one node from 1.9TB to 1.8TB to test this about half a year ago. Right now it still stores 1.86TB and the decrease has slowed down over time. So don’t count on those deletes happening at any significant speed. It’ll take a really long time to actually free up space.
The only notable thing that will happen is that the dashboard is gonna display a negative value in the “amount of free space” section.