raspbian 下 Transmission-daemon 不能随开机正常自启，如何解决？

Question

最近刚入一个 RasPi 想用来做下载机，通过 apt 装完 transmission-daemon 修改 settings.json 之后正常运行，但是每次开机之后在通过内网浏览器访问对应 9091 端口都会出现 ERR_CONNECTION_REFUSED 错误，每次都要手动 systemctl restart transmission-daemon.service 才能正常访问 web 界面。

这是 transmission-daemon 的 settings.json：

{
    "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": false,
    "download-dir": "/Download/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": 56209,
    "peer-port-random-high": 65535,
    "peer-port-random-low": 49152,
    "peer-port-random-on-start": true,
    "peer-socket-tos": "default",
    "pex-enabled": true,
    "port-forwarding-enabled": false,
    "preallocation": 1,
    "prefetch-enabled": 1,
    "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-password": "*",
    "rpc-port": 9091,
    "rpc-url": "/transmission/",
    "rpc-username": "*",
    "rpc-whitelist": "10.0.0.*",
    "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": false,
    "umask": 18,
    "upload-limit": 100,
    "upload-limit-enabled": 0,
    "upload-slots-per-torrent": 14,
    "utp-enabled": true
}

试了下开机之后 systemctl status transmission-daemon.service，结果：

● transmission-daemon.service - Transmission BitTorrent Daemon
   Loaded: loaded (/lib/systemd/system/transmission-daemon.service; enabled)
   Active: active (running) since 四 2016-09-29 17:17:09 CST; 7min ago
 Main PID: 582 (transmission-da)
   Status: "Idle."
   CGroup: /system.slice/transmission-daemon.service
           └─582 /usr/bin/transmission-daemon -f --log-error

9月 29 17:17:09 raspberrypi systemd[1]: Started Transmission BitTorrent Daemon.
9月 29 17:17:10 raspberrypi transmission-daemon[582]: [2016-09-29 17:17:10.083 CST] UDP Failed to set receive buffer: requested 4194304, got 327680 (tr-udp.c:78)
9月 29 17:17:10 raspberrypi transmission-daemon[582]: [2016-09-29 17:17:10.083 CST] UDP Failed to set send buffer: requested 1048576, got 327680 (tr-udp.c:89)

/etc/systemd/system/multi-user.target.wants/transmission-daemon.service 的配置是默认并没有改过：

[Unit]
Description=Transmission BitTorrent Daemon
After=network.target

[Service]
User=debian-transmission
Type=notify
ExecStart=/usr/bin/transmission-daemon -f --log-error
ExecReload=/bin/kill -s HUP $MAINPID

[Install]
WantedBy=multi-user.target

Answer 1

缓存设的有问题
报错第一个提示是你接受缓存是4M，但是实际UDP缓存只有32K
配置文件里面cache是4M

所以去修改UDP缓冲区大小吧，方法搜一下到处都是，我这里就不复制粘贴了