Installing Transmission BitTorrent client from the source code on CentOS 7

Configuration parameters:

installation directory – /opt/transmission

user account used to run the service – transmission

directory used to store downloads – /opt/transmission/downloads

application version – 2.92

The whole process will be divided into 3 stages: at first, we will setup a basic configuration, then an additional hard drive will be mounted to the downloads directory, and finally we will share the downloads directory using Samba

Basic configuration

add the following lines to the /etc/sysctl.d/99-sysctl.conf file to increase the size of the socket buffers

net.core.rmem_max = 4194304
net.core.wmem_max = 1048576

Comment: otherwise, the Transmission log will be populated with these messages
UDP Failed to set receive buffer: requested 4194304, got 425984 (tr-udp.c:78)
UDP Failed to set send buffer: requested 1048576, got 425984 (tr-udp.c:89)

reboot the server


install the packages required for the compilation

yum install gcc gcc-c++ libcurl-devel libevent-devel zlib-devel openssl-devel intltool

download and unpack the source code

curl -L | tar xJ -C /root

configure, compile and install the application

./configure –prefix=/opt/transmission
make install

create the /etc/profile.d/ file with the following content in order to add the binary files path into the PATH environment variable

export PATH=$PATH:/opt/transmission/bin

add the man pages path to the /etc/man_db.conf file

MANDATORY_MANPATH /opt/transmission/share/man

create the /opt/transmission/settings.json configuration file

«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»: «»,
«bind-address-ipv6»: «::»,
«blocklist-enabled»: false,
«blocklist-url»: «»,
«cache-size-mb»: 512,
«dht-enabled»: true,
«download-dir»: «/opt/transmission/downloads»,
«download-queue-enabled»: false,
«download-queue-size»: 5,
«encryption»: 2,
«idle-seeding-limit»: 30,
«idle-seeding-limit-enabled»: false,
«incomplete-dir»: «/opt/transmission/downloads»,
«incomplete-dir-enabled»: false,
«lazy-bitfield-enabled»: true,
«lpd-enabled»: false,
«message-level»: 2,
«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,
«pidfile»: «/opt/transmission/»,
«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»: false,
«rpc-authentication-required»: true,
«rpc-bind-address»: «»,
«rpc-enabled»: true,
«rpc-password»: «some_password»,
«rpc-port»: 9091,
«rpc-url»: «/transmission/»,
«rpc-username»: «some_user»,
«rpc-whitelist»: «»,
«rpc-whitelist-enabled»: true,
«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»: 100,
«speed-limit-up-enabled»: false,
«start-added-torrents»: true,
«trash-original-torrent-files»: true,
«umask»: 63,
«upload-slots-per-torrent»: 14,
«utp-enabled»: true,
«watch-dir»: «/opt/transmission/watch»,
«watch-dir-enabled»: true

Comment 1: when the service starts the value of the rpc-password parameter is substituted with its hash

Comment 2: all the configuration changes should be made with the service stopped, otherwise they will be lost

create the required directories

mkdir /opt/transmission/{blocklists,downloads,resume,torrents,watch}

create a user account for running the service

useradd -M transmission
passwd some_password

change owners and permissions of the /opt/transmission directory

chown -R transmission:transmission /opt/transmission
find /opt/transmission -type d -exec chmod 700 {} \;
find /opt/transmission -type f -exec chmod 600 {} \;
chmod 700 /opt/transmission/bin/*

create the /usr/lib/systemd/system/transmission.service unit file

Description=Transmission BitTorrent Client

ExecStart=/opt/transmission/bin/transmission-daemon —foreground —pid-file /opt/transmission/ —config-dir /opt/transmission —logfile /opt/transmission/transmission.log


reload the systemd configuration

systemctl daemon-reload

start the service

systemctl start transmission

add a torrent using the command

transmission-remote –auth some_user:some_password –add /file/path

list torrents using the command

transmission-remote –auth some_user:some_password –list

remove a torrent using the command

transmission-remote –auth some_user:some_password –torrent torrent_id –remove

Mount an additional hard drive

determine the right hard drive

fdisk -l

Comment: let’s assume that the hard drive is named /dev/sdb

create a new LVM physical volume

pvcreate /dev/sdb

create a new LVM volume group

vgcreate downloads_vg /dev/sdb

create a new LVM logical volume

lvcreate -l 100%FREE -n downloads_lv downloads_vg

create a filesystem on the LVM logical volume

mkfs –type ext4 /dev/downloads_vg/downloads_lv

add the following line to the /etc/fstab file in order to enable mounting of the LVM logical volume on the system startup

/dev/downloads_vg/downloads_lv /opt/transmission/downloads ext4 defaults 0 0

mount all filesystems listed in the /etc/fstab file

mount -a

change owners and permissions of the root directory of the LVM logical volume

chown -R transmission:transmission downloads
chmod -R 700 downloads

Configure Samba

install Samba

yum install samba

change the SELinux context of the /opt/transmission/downloads and /opt/transmission/watch directories to samba_share_t as described here

replace the content of the /etc/samba/smb.config file with the following

security = user
server role = standalone
server min protocol = SMB2
server max protocol = SMB3
passdb backend = tdbsam:/etc/samba/passdb.tdb
log level = 1

guest ok = no
writable = yes
browsable = yes
create mask = 0700
directory mask = 0700

guest ok = no
writable = yes
browsable = yes
create mask = 0700
directory mask = 0700

create a Samba user account

smbpasswd -a transmission

Comment 1: as a result the file /etc/samba/passdb.tdb will be created

Comment 2: although authentication will be performed via the file, the corresponding system account must exist and its password must be set

change owners and permissions of the /etc/samba directory

chmod 400 /etc/samba/*

test the configuration


restart Samba

systemctl restart smb

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