GNOME's tracker is a CPU and privacy hog. There's a pretty good case as to why it's neither useful nor necessary here: http://lduros.net/posts/tracker-sucks-thanks-tracker/
After discovering it chowing 2 cores, I decided to go about disabling it.
~/.cache/tracker
~/.local/share/tracker
After wiping and letting it do a fresh index on my almost new desktop, the total size of each of these directories was a whopping 3.9 GB!
On my Ubuntu GNOME setup, I found the following files:
$ ls /etc/xdg/autostart/tracker-*
/etc/xdg/autostart/tracker-extract.desktop
/etc/xdg/autostart/tracker-miner-fs.desktop
/etc/xdg/autostart/tracker-store.desktop
/etc/xdg/autostart/tracker-miner-apps.desktop
/etc/xdg/autostart/tracker-miner-user-guides.desktop
You can disable these by adding Hidden=true to them. It's best done in your
local .config directory because 1) you don't need sudo and 2) you are pretty
much guaranteed that your changes won't be blown away by an update.
Running tracker will give you a vast array of tools to check on tracker and
manage its processes.
$ tracker
usage: tracker [--version] [--help]
<command> [<args>]
Available tracker commands are:
daemon Start, stop, pause and list processes responsible for indexing content
info Show information known about local files or items indexed
index Backup, restore, import and (re)index by MIME type or file name
reset Reset or remove index and revert configurations to defaults
search Search for content indexed or show content by type
sparql Query and update the index using SPARQL or search, list and tree the ontology
sql Query the database at the lowest level using SQL
status Show the indexing progress, content statistics and index state
tag Create, list or delete tags for indexed content
See 'tracker help <command>' to read about a specific subcommand.
This disables everything but tracker-store, which even though it has a
.desktop file, seems tenacious and starts up anyway. However, nothing gets
indexed.
tracker daemon -t
cd ~/.config/autostart
cp -v /etc/xdg/autostart/tracker-*.desktop ./
for FILE in tracker-*.desktop; do echo Hidden=true >> $FILE; done
rm -rf ~/.cache/tracker ~/.local/share/tracker
Note that tracker daemon -t is for graceful termination. If you are having
issues terminating processes or just want to take your frustration out,
tracker daemon -k immediately kills all processes.
After this is done, tracker-store will still start on the next boot. However,
nothing will be indexed. Your disk and CPU will be better for wear.
$ tracker status
Currently indexed: 0 files, 0 folders
Remaining space on database partition: 123 GB (78.9%)
All data miners are idle, indexing complete