Live from arcstats (dirty), dmu_tx (throttled writes), each pool's txgs (bytes synced to disk) and objset kstats (bytes from programs). A landing tier — a mergerfs pool whose first branch is fast storage and whose last is a ZFS dataset — is detected from mergerfs's branch xattr; a mover status file in /run/landing-mover/ adds its queue, the file in flight and totals. Sensors zfs.write.*, zfs.<pool>.write_bps|logical_bps and zfs.<pool>.landing.* carry the history. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>