I have a purge/salvage question. I have a volume with 1.254 TB. I have
152 GB free 12%, 352 GB of purgable 28%, and 749 GB of used space. I am
trying to understand the high and low water mark settings for purging
data. The defaults are low water of 10% and high water of 20%. So my
understanding is when I get down to around 10% or 125 GB of free space
the server will begin purging the oldest data until it reaches the high
water mark which is 20 % or roughly 250 GB of free space. I have
several questions.

When the server hits the low water mark and begins purging does it purge
all of this data immediately? For example I hit my 125 GB low water mark
in the morning and bam within an hour or two I know have 250 GB of free
space? I assume then I should see a good drop in my purgable space from
like 352 GB to 227 GB or 18%?

I am also trying to understand what is going to happen as my "used
space" continues to increase. As my used space creeps up above 80% I
assume at some point it will become the ceiling for the high water mark
and eat away at what amount I have for purgeable. At what point do you
lose the ability to salvage files?