BitTorrent – Troubleshooting Torrent File Download Issues

bittorrent

I have created a torrent from target.bz2 on my vps.

transmission-create  -o target.torrent -t udp://tracker.opentrackr.org:1337/announce  -s 2048  target.bz2

Port 51413 was opened on my pvs.
Then send the target.torrent to my friend with email,he start a download with aria2c:

aria2c target.torrent 
06/03 12:35:11 [NOTICE] Downloading 1 item(s)
06/03 12:35:11 [NOTICE] IPv4 DHT: listening on UDP port 6893
06/03 12:35:11 [ERROR] Exception caught
Exception: [DefaultBtProgressInfoFile.cc:280] errorCode=1 info hash mismatch. expected: b5c4a65adbd5d2ea3e07f2d4207da4c4dee9a0ba, actual: ab172fda6a8b41155cf16e35e49883710169e2bf
06/03 12:35:11 [NOTICE] Download GID#e7239e7f5e170038 not complete: /root/target.bz2                                                                               
Download Results:
gid   |stat|avg speed  |path/URI
======+====+===========+=======================================================
e7239e|ERR |        n/a|/root/target.bz2

Status Legend:
(ERR):error occurred.

aria2 will resume download if the transfer is restarted.
If there are any errors, then see the log file. See '-l' option in help/man page for details.

Try with transmission-cli:

transmission-cli  target.torrent -w  /tmp

It encounter error:

Tracker gave an error:: Invalid passkey (0 - )

Download it with qtorrent.

enter image description here

How to make torrent clien know the resources target.bz2 located in my vps?

Both target.bz2 and target.torrent are on my vps.

cd  /tmp
ls  
target.bz2
target.torrent

Strange enough, both target.bz2 and target.torrent in my vps /tmp direcotry,i can't download the /tmp/target.bz2 into /home with command transmission-cli /tmp/target.torrent -w /home.
enter image description here

Analyse the torrent created for my friend downloading with python(omit many pieces).

>>> import torrent_parser as tp
>>> data = tp.parse_torrent_file('/tmp/target.torrent')
>>> data
{'created by': 'Transmission/2.92 (14714)', 'encoding': 'UTF-8', 'announce': 'udp://tracker.opentrackr.org:1337/announce', 
'creation date': 1591488553, 'info': {'pieces': 
['bb47ffb395620d2541a094bc33c92a65b7a02425', 'c572be1020cab80b00953bc596ad0b1b62392e53', 
], 'name': 'target.bz2', 'length': 216094557, 'piece length': 4194304, 'private': 0}}

Download a debian torrent(renamed ) and analyse it(omit many pieces).

>>> import torrent_parser as tp
>>> data = tp.parse_torrent_file('/debian.torrent')
>>> data
{'httpseeds': ['https://cdimage.debian.org/cdimage/release/10.4.0//srv/cdbuilder.debian.org/dst/deb-cd/weekly-builds/amd64/iso-dvd/debian-10.4.0-amd64-DVD-1.iso', 
'https://cdimage.debian.org/cdimage/archive/10.4.0//srv/cdbuilder.debian.org/dst/deb-cd/weekly-builds/amd64/iso-dvd/debian-10.4.0-amd64-DVD-1.iso'], 
'info': {'pieces': ['b49a7c062b92a8618998c919ee3ea122ed348c3f',]
'name': 'debian-10.4.0-amd64-DVD-1.iso', 'piece length': 1048576, 'length': 3955556352}, 
'comment': '"Debian CD from cdimage.debian.org"', 'announce': 'http://bttracker.debian.org:6969/announce', 'creation date': 1589025382}

Which primary elements lost in my created torrent?

Best Answer

Aria2c

info hash mismatch. expected: b5c4a65adbd5d2ea3e07f2d4207da4c4dee9a0ba, actual: ab172fda6a8b41155cf16e35e49883710169e2bf

The first error you had with aria2c is related to an existing target file on the download location /root/target.bz2 that have a hash mismatch, you need to delete/recreate the target file. (but this is probably not the only issue of your question)

This is may be caused by an improper transfer of the generated torrent file from the server, note that you can not use cat to copy your torrent file from the server.

Transmission

The torrent creation is correct, your torrent is just not seeding, on your server run:

transmission-cli -v /tmp/target.torrent -w /tmp/ -p 51413

To make the file available for clients, this command must output Seeding, uploading to 0 of 0 peer(s), 0 kB/s [0.00]... and must be kept running.

How to create a torrent on a VPS:

In this how-to demo we will generate a random file with dd and use transmission. note that uploading and downloading from the server itself may be tricky or not possible with transmission as it require additional configuration. also note that we can use the package transmission-daemon for a proper torrent server (not used in this mini how-to).

  1. Install the package transmission
  2. Generate a random file
    mkdir /tmp/tmp
    cd /tmp/tmp
    dd if=/dev/random of=/tmp/tmp/file.my count=100000
  1. Open the TCP/UDP ports 51413
  2. Create the torrent file
    transmission-create -o /tmp/tmp/tor.torrent -t udp://tracker.opentrackr.org:1337/announce -s 1024 /tmp/tmp/file.my

  1. Copy the torrent file to the client (cat may not be used)

  2. Enable a seeder on the server, the following command must output Seeding, uploading to 0 of 0 peer(s), 0 kB/s [0.00]... and must be kept running.

    transmission-cli -v /tmp/tmp/tor.torrent -w /tmp/tmp/ -p 51413
  1. Open the torrent file on the client with the preferred torrent client.

Links

Transmission-create, transmission server.

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