Install transmission on Centos 7

Step 1. First, you need to enable the EPEL repository on your system.

yum install epel-release
yum -y update

Step 2. Installing Transmission on CentOS 7.

Just run the following command to install Transmission:

yum install transmission-cli transmission-common transmission-daemon

Once complete, you can verify Transmission is installed by running the below command:

systemctl start transmission-daemon.service
systemctl stop transmission-daemon.service

Step 3. Configuration Transmission.

Edit the transmission settings.json config file:

nano /var/lib/transmission/.config/transmission-daemon/settings.json

OK now let’s edit the settings (to your liking) and don’t forget to save them.

{
"alt-speed-down": 50,
"alt-speed-enabled": false,
"alt-speed-time-begin": 540,
"alt-speed-time-day": 127,
"alt-speed-time-enabled": false,
"alt-speed-time-end": 1020,
"alt-speed-up": 50,
"bind-address-ipv4": "0.0.0.0",
"bind-address-ipv6": "::",
"blocklist-enabled": false,
"blocklist-url": "http://www.example.com/blocklist",
"cache-size-mb": 4,
"dht-enabled": true,
"download-dir": "/opt/transmission/",
"download-limit": 100,
"download-limit-enabled": 0,
"download-queue-enabled": true,
"download-queue-size": 5,
"encryption": 1,
"idle-seeding-limit": 30,
"idle-seeding-limit-enabled": false,
"incomplete-dir": "/var/lib/transmission-daemon/Downloads",
"incomplete-dir-enabled": false,
"lpd-enabled": false,
"max-peers-global": 200,
"message-level": 1,
"peer-congestion-algorithm": "",
"peer-id-ttl-hours": 6,
"peer-limit-global": 200,
"peer-limit-per-torrent": 50,
"peer-port": 51413,
"peer-port-random-high": 65535,
"peer-port-random-low": 49152,
"peer-port-random-on-start": false,
"peer-socket-tos": "default",
"pex-enabled": true,
"port-forwarding-enabled": false,
"preallocation": 1,
"prefetch-enabled": true,
"queue-stalled-enabled": true,
"queue-stalled-minutes": 30,
"ratio-limit": 2,
"ratio-limit-enabled": false,
"rename-partial-files": true,
"rpc-authentication-required": true,
"rpc-bind-address": "0.0.0.0",
"rpc-enabled": true,
"rpc-host-whitelist": "",
"rpc-host-whitelist-enabled": true,
"rpc-password": "{02ffc39b889c8c2d8523778c0f56a5092396d3a4FhyM7bLq",
"rpc-port": 9091,
"rpc-url": "/transmission/",
"rpc-username": "transmission",
"rpc-whitelist": "127.0.0.1",
"rpc-whitelist-enabled": false,
"scrape-paused-torrents-enabled": true,
"script-torrent-done-enabled": false,
"script-torrent-done-filename": "",
"seed-queue-enabled": false,
"seed-queue-size": 10,
"speed-limit-down": 100,
"speed-limit-down-enabled": false,
"speed-limit-up": 10,
"speed-limit-up-enabled": false,
"start-added-torrents": true,
"trash-original-torrent-files": false,
"umask": 2,
"upload-limit": 100,
"upload-limit-enabled": 0,
"upload-slots-per-torrent": 14,
"utp-enabled": true
}

After editing and saving the settings.json file, start the transmission-daemon:

systemctl start transmission-daemon.service

Step 4. Accessing Transmission.

Transmission BitTorrent Client will be available on HTTP port 9091 by default, if needed, allow port 9091 from firewalld. Open your favorite browser and navigate to

http://yourdomain.com:9091

or http://server-ip:9091. You should be greeted with the Transmission WebUI. The default username and password are-

transmssion

After logging in, you will notice that the value for the RPC-password inside the settings.json file will be hashed. If you are using a firewall, please open port 80 to enable access to the control panel.

If you wish to use any custom folder to store files like on above json configuration- /opt/transmission, you need to change ownership with transmission on the above directory-

chown -R transmission: /opt/transmission

Ref:
https://idroot.us/install-transmission-centos-7/
https://blog.jackiesung.com/linux/how-to-install-transmission-torrent-client-on-centos-7-and-debian.html