Incomplete downloads and seeded files are counted twice on a Mac
A torrent client pre-allocates space, keeps partial files and often seeds a second copy. Where the space goes and how to reclaim it.
A torrent client can use far more space than the files it has actually downloaded, for three reasons that all look like bugs and are all deliberate: pre-allocation, incomplete folders, and copying rather than moving on completion.
The three causes
- Pre-allocation. Many clients reserve the full size of a file when the transfer starts, so a 40 GB download occupies 40 GB from the first minute.
- Separate incomplete folders. Clients often download to one folder and move to another on completion. An interrupted transfer stays in the first one forever.
- Copy instead of move. If the incomplete and complete folders are on different volumes, completion copies rather than moves, and the original may remain.
Find what is actually there
du -sh ~/Downloads ~/Documents/*orrent* 2>/dev/null | sort -h
find ~ -maxdepth 4 \( -name '*.part' -o -name '*!qB' -o -name '*.partial' \) \
-size +100M -exec ls -lh {} + 2>/dev/null | sort -k5 -h | tail -15Those extensions are the incomplete markers used by the common clients. Anything on that list from more than a few weeks ago is a transfer that will not resume, and it is holding its full pre-allocated size.
Seeding, and the second copy
Files you continue to seed are files you are keeping, which is the point, but people forget them because the client is minimised. Check the client's own list rather than the folder: removing a torrent from the client usually offers to delete its data, and that is the tidy route.
The settings worth changing once
- Turn off pre-allocation if you download over unreliable connections and abandon transfers often.
- Set the incomplete and complete folders on the same volume, so completion is a move rather than a copy.
- Set a seeding ratio limit so torrents stop being kept indefinitely.
- Point the download folder at an external drive if this is a regular activity.
The Downloads folder itself is worth a look at the same time, since it collects everything else, and clearing it out is the easiest space on any Mac.
Common questions
Why does my torrent client use more space than the files?
Pre-allocation reserves the full size of each file when a transfer starts, and interrupted downloads keep that reservation. Separate incomplete and complete folders on different volumes can also leave two copies.
Where are incomplete downloads stored?
In whichever incomplete folder the client is configured to use, with extensions such as .part or !qB. A find command for those patterns shows abandoned transfers holding their full pre-allocated size.
Is it safe to delete partial download files?
Yes, if the transfer is no longer in the client's list or you do not intend to resume it. Removing the torrent through the client and choosing to delete data is tidier than deleting files by hand.
How do I stop torrents filling my disk?
Turn off pre-allocation, keep incomplete and complete folders on the same volume, set a seeding ratio limit so torrents do not seed indefinitely, and point downloads at an external drive.