DB::Exception: Cannot select parts for optimization: Part 202005_0_2566_8 has already been assigned a merge into 202005_0_2566_9.

SELECT *
FROM system.disks

┌─name────┬─path──────────────────────┬────free_space─┬────total_space─┬─keep_free_space─┐
│ default │ /disk3/clickhouse-tiered/ │ 6466726883328 │ 15240779816960 │               0 │
│ disk4   │ /disk4/clickhouse-tiered/ │ 7859383476224 │ 15240779816960 │               0 │
└─────────┴───────────────────────────┴───────────────┴────────────────┴─────────────────┘

# df -h /var/lib/clickhouse
Filesystem      Size  Used Avail Use% Mounted on
/dev/nvme0n1p1  1.8T  1.5T  281G  84% /