Transmission
Transmission is a light-weight and cross-platform BitTorrent client. It is the default BitTorrent client in many Linux distributions.
Contents
Installation
There are several options in official repositories:
- transmission-cli - daemon, with CLI, and web client (http://localhost:9091) interfaces.
- transmission-remote-cli - Curses interface for the daemon.
- transmission-gtk - GTK3 package.
- transmission-qt - Qt5 package.
Configuring the GUI version
Both GUI versions, transmission-gtk and transmission-qt, can function autonomously without a formal back-end daemon.
GUI versions are configured to work out-of-the-box, but the user may wish to change some of the settings. The default path to the GUI configuration files is ~/.config/transmission
.
A guide to configuration options can be found on the Transmission web site: https://trac.transmissionbt.com/wiki/EditConfigFiles#Options.
GTK+ temporary cosmetic fix
With GTK+ 3.18, transmission-gtk shows black borders in random places; these can be hidden via gtk.css
:
~/.config/gtk-3.0/gtk.css
.tr-workarea .overshoot, .tr-workarea .undershoot { border: none; }
Transmission-daemon and CLI
The commands for transmission-cli are:
- transmission-daemon: starts the daemon.
- transmission-remote: invokes the CLI for the daemon, whether local or remote, followed by the command you want the daemon to execute.
- transmission-remote-cli: (requires transmission-remote-cli) starts the curses interface for the daemon, whether local or remote.
- transmission-cli: starts a non-daemonized local instance of transmission, for manually downloading a torrent.
- transmission-show: returns information on a given torrent file.
- transmission-create: creates a new torrent.
- transmission-edit: add, delete, or replace a tracker's announce URL.
Starting and stopping the daemon
As explained in #Choosing a user, the transmission
daemon can be run:
- As the user transmission, by running as root:
# systemctl start transmission
The daemon can then be stopped with:# systemctl stop transmission
- As your own user, by running under your user name:
$ transmission-daemon
The daemon can then be stopped with:$ killall transmission-daemon
- Starting (and stopping)
transmission.service
with systemctl will use the user set in #Choosing a user. Note that the name of the systemd service istransmission.service
, nottransmission-daemon.service
.
Starting the daemon will create an initial transmission configuration file. See #Configuring the daemon.
An alternative option to stop transmission is to use the transmission-remote command:
$ transmission-remote --exit
Autostart at boot
Enable transmission.service
using systemd.
The daemon is started after network.service
was initialised. However, if you enable the service dhcpcd
as opposed to the device-specific service, such as dhcpcd@enp1s0.service
for example, it may happen that Transmission is started too early and cannot bind to the network interface. Thus, the web interface is unreachable. A possible solution is to add the Requires
line to the unit's configuration file:
/etc/systemd/system/transmission.service.d/fixdep.conf
[Unit] Requires=network.target
Run only while connected to network
Netctl
It may only be desirable to run transmission on certain networks. The following script checks that the connection is to a list of authorized networks and then proceeds to launch transmission-daemon.
/etc/netctl/hooks/90-transmission.sh
#!/bin/bash # The SSIDs for which we enable this. declare -A ssids=( ["network_1"]=y ["network_2"]=y ) if [[ ${ssids[$SSID]} ]]; then case $ACTION in CONNECT|REESTABLISHED) # Need to wait, otherwise doesn't seem to bind to 9091. sleep 30 systemctl start transmission ;; *) systemctl stop transmission ;; esac fi
Wicd
Create a start script in folder /etc/wicd/scripts/postconnect
, and a stop script in folder /etc/wicd/scripts/predisconnect
. Remember to make them executable. For example:
/etc/wicd/scripts/postconnect/transmission
#!/bin/bash systemctl start transmission
/etc/wicd/scripts/predisconnect/transmission
#!/bin/bash systemctl stop transmission
NetworkManager
Choosing a user
Choose how you want to run transmission
:
- As a separate user,
transmission
by default (recommended for increased security).
By default, transmission creates a user and a group transmission
, with its home files at /var/lib/transmission/
, and runs as this "user". This is a security precaution, so transmission, and its downloads, have no access to files outside of /var/lib/transmission/
. Configuration, operation, and access to downloads needs to be done with "root" privileges (e.g. by using sudo).
- Under the user's own user name.
To set this up, override the provided service file and specify your username:
/etc/systemd/system/transmission.service.d/username.conf
[Service] User=your_username
Configuring the daemon
Create an initial configuration file by starting the daemon.
- If running Transmission under the username
transmission
, the configuration file will be located at/var/lib/transmission/.config/transmission-daemon/settings.json
.
- If running Transmission under your own username, the configuration file will be located at
~/.config/transmission-daemon/settings.json
.
One can customize the daemon by using a Transmission client or using the included web interface accessible via http://localhost:9091 in a supported browser.
A guide to configuration options can be found on the Transmission web site: https://trac.transmissionbt.com/wiki/EditConfigFiles#Options
A recommendation for those running under username transmission
is to create a shared download directory with the correct permissions to allow access to both the transmission
user and system users, and then to update the configuration file accordingly. For example:
# mkdir /mnt/data/torrents # chown -R facade:transmission /mnt/data/torrents # chmod -R 775 /mnt/data/torrents
Now /mnt/data/torrents
will be accessible for the system user facade
and for the transmission
group to which the transmission
user belongs. Making the target directory world read/writable is highly discouraged (i.e. do not chmod the directory to 777). Instead, give individual users/groups appropriate permissions to the appropriate directories.
An alternative is to add your user to the transmission
group (#usermod -a -G transmission yourusername
) and then modify the permissions on the /var/lib/transmission
and /var/lib/transmission/Downloads
directories to allow rwx
access by members of the transmission
group.
Watch dir
If you want to Automatically add .torrent files from a folder, but you find that the watch-dir
and watch-dir-enabled
options set in the config file do not work, you can start the transmission daemon with the flag -c /path/to/watch/dir
.
If you're using systemd, edit the unit file located at /etc/systemd/system/transmission.service
.
Troubleshooting
UDP Failed to set receive/sent buffer
The error messages UDP Failed to set receive buffer
and UDP Failed to set sent buffer
mean that Transmission would like a bigger sent and receive buffer. These buffers can be changed by adding the following file:
/etc/sysctl.d/60-net_buffer.conf
net.core.rmem_max = 16777216 net.core.wmem_max = 4194304
To load the new configuration run # sysctl --system
and then reload Transmission.