Transmission

I'm sitting here watching a file download. It's at 99.5% and says 1 minute remaining.

I understand how the "1 minute remaining" figure can go up, because that's about the network speed, seeds, peers, etc.

But how come the "99.5%" figure can go back down?

One minute I'm at 99.5% and 348MB downloaded, next minute it's 99.4% and the total size downloaded is less than 348MB.

This is of course very frustrating, but also technically puzzling.

Oh, OK. That kind of makes sense. What do I do to stop that happening?

After 5 bad pieces, Transmission blocks that peer for the session automatically. Blocklists can help but some people (not in the blocklist) touch their files and modify something without having the bittorrent client rescan it. It sends out bad pieces without knowing it.

I have to say, I've been looking at the phenomenon and it seems to happen way too much at the very end of a download.

It could just be confirmation bias, because I'm not examining downloads too closely when we're at the beginning. The difference between ten percent and ten point five per cent is irrelevant. But I'm watching a certain torrent download now and the very last one per cent is taking an incredible amount of time.

For instance, I've been watching a torrent for fifteen minutes now. When I started, there were just 55 seconds remaining. And there still are. It's got as far as 99.9% downloaded, then gone back as far as 98.5% downloaded. Many many many times.

Here's the log -- some pieces are failing over and over, some once, but there are a lot of failures:


2010-10-11 19:33:24 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 121, which was just downloaded, failed its checksum test
2010-10-11 19:33:27 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:33:30 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 136, which was just downloaded, failed its checksum test
2010-10-11 19:33:30 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 338, which was just downloaded, failed its checksum test
2010-10-11 19:33:31 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 60, which was just downloaded, failed its checksum test
2010-10-11 19:33:31 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 55, which was just downloaded, failed its checksum test
2010-10-11 19:33:32 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 16, which was just downloaded, failed its checksum test
2010-10-11 19:33:34 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:33:37 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:33:44 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 506, which was just downloaded, failed its checksum test
2010-10-11 19:33:45 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 620, which was just downloaded, failed its checksum test
2010-10-11 19:33:45 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 548, which was just downloaded, failed its checksum test
2010-10-11 19:33:49 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:33:58 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 13, which was just downloaded, failed its checksum test
2010-10-11 19:34:02 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:34:05 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 170, which was just downloaded, failed its checksum test
2010-10-11 19:34:48 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 504, which was just downloaded, failed its checksum test
2010-10-11 19:34:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:35:41 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:35:42 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 46, which was just downloaded, failed its checksum test
2010-10-11 19:35:46 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:35:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 136, which was just downloaded, failed its checksum test
2010-10-11 19:36:29 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:36:46 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:36:47 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 509, which was just downloaded, failed its checksum test
2010-10-11 19:37:07 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 136, which was just downloaded, failed its checksum test
2010-10-11 19:37:24 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:37:25 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 506, which was just downloaded, failed its checksum test
2010-10-11 19:37:41 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 136, which was just downloaded, failed its checksum test
2010-10-11 19:37:42 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:37:54 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 459, which was just downloaded, failed its checksum test
2010-10-11 19:37:57 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 305, which was just downloaded, failed its checksum test
2010-10-11 19:38:00 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:38:18 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 136, which was just downloaded, failed its checksum test
2010-10-11 19:38:31 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:38:41 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:39:08 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 45, which was just downloaded, failed its checksum test
2010-10-11 19:39:21 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:39:34 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 198, which was just downloaded, failed its checksum test
2010-10-11 19:39:43 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:39:59 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:40:08 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:40:17 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:40:32 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 506, which was just downloaded, failed its checksum test
2010-10-11 19:41:05 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:41:21 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:41:28 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 190, which was just downloaded, failed its checksum test
2010-10-11 19:41:39 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:41:52 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 677, which was just downloaded, failed its checksum test
2010-10-11 19:41:57 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:41:58 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:41:58 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 177, which was just downloaded, failed its checksum test
2010-10-11 19:42:16 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:42:18 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:42:25 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:42:43 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 548, which was just downloaded, failed its checksum test
2010-10-11 19:42:44 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:42:44 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 677, which was just downloaded, failed its checksum test
2010-10-11 19:42:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:43:00 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:43:17 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:43:21 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 190, which was just downloaded, failed its checksum test
2010-10-11 19:43:28 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:43:38 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:43:38 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:43:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 548, which was just downloaded, failed its checksum test
2010-10-11 19:44:00 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 677, which was just downloaded, failed its checksum test
2010-10-11 19:44:04 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:44:21 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:44:24 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:44:24 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 548, which was just downloaded, failed its checksum test
2010-10-11 19:44:35 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 190, which was just downloaded, failed its checksum test
2010-10-11 19:44:36 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:44:38 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 677, which was just downloaded, failed its checksum test
2010-10-11 19:44:38 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:44:50 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:45:13 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:45:16 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 311, which was just downloaded, failed its checksum test
2010-10-11 19:45:20 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:45:43 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 190, which was just downloaded, failed its checksum test
2010-10-11 19:45:47 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:45:49 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 16, which was just downloaded, failed its checksum test
2010-10-11 19:45:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:45:57 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:46:10 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 548, which was just downloaded, failed its checksum test
2010-10-11 19:46:22 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 299, which was just downloaded, failed its checksum test
2010-10-11 19:46:25 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:47:02 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 83, which was just downloaded, failed its checksum test
2010-10-11 19:47:31 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 136, which was just downloaded, failed its checksum test
2010-10-11 19:47:50 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:48:02 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 299, which was just downloaded, failed its checksum test
2010-10-11 19:48:09 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:48:09 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:48:09 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 46, which was just downloaded, failed its checksum test
2010-10-11 19:48:13 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:48:20 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 83, which was just downloaded, failed its checksum test
2010-10-11 19:48:29 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 14, which was just downloaded, failed its checksum test
2010-10-11 19:48:38 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 16, which was just downloaded, failed its checksum test
2010-10-11 19:48:40 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 299, which was just downloaded, failed its checksum test
2010-10-11 19:48:45 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 215, which was just downloaded, failed its checksum test
2010-10-11 19:48:52 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 20, which was just downloaded, failed its checksum test
2010-10-11 19:48:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:48:55 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:49:11 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 83, which was just downloaded, failed its checksum test
2010-10-11 19:49:25 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:49:40 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:49:56 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 87, which was just downloaded, failed its checksum test
2010-10-11 19:49:58 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 83, which was just downloaded, failed its checksum test
2010-10-11 19:50:16 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:50:21 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:50:45 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:50:48 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:50:58 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:51:01 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 119, which was just downloaded, failed its checksum test
2010-10-11 19:51:08 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:51:10 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:51:23 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 87, which was just downloaded, failed its checksum test
2010-10-11 19:51:23 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:51:31 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 677, which was just downloaded, failed its checksum test
2010-10-11 19:51:39 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:51:43 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:51:53 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test
2010-10-11 19:52:07 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 269, which was just downloaded, failed its checksum test
2010-10-11 19:52:10 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 25, which was just downloaded, failed its checksum test
2010-10-11 19:52:15 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 677, which was just downloaded, failed its checksum test
2010-10-11 19:52:22 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 83, which was just downloaded, failed its checksum test
2010-10-11 19:52:27 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 674, which was just downloaded, failed its checksum test
2010-10-11 19:52:31 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 193, which was just downloaded, failed its checksum test
2010-10-11 19:52:38 +1100 peer-mgr.c:1466 [Error] [FILENAME]: Piece 460, which was just downloaded, failed its checksum test

It's the same several pieces. When Transmission gets to the end of the torrent, it switches to endgame mode. When it does this, it requests blocks from 3 people at once. This is so the download finishes fast. If a bad peer hasn't been kicked off by endgame, the final pieces will get corrupt and Transmission will have to throw them all away and place blame on all of the ones involved. You can't really stop the poisoning from happening other than using more reputable swarms.