pub const DISK_LINE_PERCENT: u64 = 80;Expand description
The disk line: once the filesystem holding a store is this full, the lazy pool gives its OLDEST segments back, whatever its own budget says.
Rickard, 2026-09-28: “add a deletion of the old objects in case 80 % disk
is taken”. The budget and the global line are both fractions of the
filesystem’s SIZE, so a disk filled by packs — the truth, never evictable —
never moved either of them: the cache kept its full 10 % while pushes were
refused at the floor. 80 % is also where the appliance’s grow batcher
queues a growth (monetize grow_high_water_percent), so the cache is
handing space back at the moment the disk is asked to grow, not after.
Oldest first, not cheapest first: under pressure the question is “what has
nobody needed for longest”, and the rebuild cost of an object nobody reads
is paid by nobody. The eager pool is still never touched. 0 = off.