zpool-ddtprune.8

ZPOOL-DDTPRUNE(8) System Manager's Manual ZPOOL-DDTPRUNE(8)

zpool-ddtprune — Prunes the oldest entries from the single reference dedup table(s)

zpool ddtprune -d days | -p percentage pool

This command prunes older unique entries from the dedup table. As a complement to the dedup quota feature, allows removal of older non-duplicate entries to make room for newer duplicate entries.

The amount to prune can be based on a target percentage of the unique entries or based on the age (i.e., every unique entry older than N days).

A unique entry holding more than one copy of its block, as written with greater than 1, is not pruned: a block written before the entry gained its extra copies may still refer to it, and pruning it would leak the copies that block does not refer to.

zdb(8), zpool-status(8)

October 18, 2026 Ubuntu