I installed Transmission a long time ago on my Raspberry Pi and couldn't figure out why each time I rebooted my Raspberry Pi I was forced to restart transmission-daemon otherwise Transmission web interface wasn't reachable.
Because transmission-daemon isn't logging to a file by default, I had to search how to enable this.
You have to edit the service launched by systemd located at:
And append those arguments to the command that launches transmission-daemon:
--log-debug --logfile /var/log/transmission.log
--log-debug but I'm not sure if this is
mandatory. Don't forget to create the file and chown it to debian-transmission
user otherwise the daemon will not be able to write it.
I was able to reboot and see transmission logs with this error:
getaddrinfo: address family for nodename not supported (trevent.c:216)
After some research, I found that this error was raised because my Raspberry Pi didn't have an IPv6 address.
As I didn't use IPv6, I disabled it by editing
/etc/sysctl.conf and adding
this line (credit to Leow Kah Man):
net.ipv6.conf.all.disable_ipv6 = 1
Now, transmission-daemon starts as expected at boot time.