Oh, I just read your message again, and I see that I
didn't answer your
question. :D I admit I don't know how MAX AVAIL is calculated, and whether
it takes things like imbalance into account (it might).
It does. It’s calculated relative to the most-full OSD in the pool, and the full_ratio is
also applied to account for the space it effectively reserves. Significant imbalance in
OSD fullness will result in this figure being smaller than one expects from the amount of
raw capacity unused. This is subtle and often misunderstood.
>> Sum of POOLS/MAX AVAIL is about 840 GiB
Those numbers can’t be meaningfully summed, since most or all of those pools are sharing
the same OSDs.