Jump to content

! Recheck -> 100% File Becomes 99.9% (Last Piece Lost)


Guest

Recommended Posts

Hi,

There are a few threads that may or may not be related to this problem, but the one I am describing is more specific and definitely unrelated to the ones that I just found in the search.

The problem I have seen quite a few times is one where:

1) A torrent is downloaded (all files are 100% done)

2) A file in the torrent is flagged as "don't download"

3) A recheck is performed to update µTorrent so as to avoid the "Element not found" error

The file previous to the one that was flagged as "don't download" is now shown as being 99.9%. Well, it is not exactly 99.9%, it can be whatever; the point is that the last piece, be it 128KB or 4MB, is now detected as incomplete even though it is fine. (Just to clarify, I mean the file is now not 100%, obviously the torrent won't be).

I have not had a chance to test whether it still occurs if the file that was flagged as "don't download" is still present (it certainly does if it is removed from the directory). I also have not had a chance to test whether it gets fixed if you put that file back and flag it as normal again.

I suspect that it may have something to do with file/piece boundaries: not all files end neatly at the end of a piece—in fact that's quite rare—so the piece contains the end of one file and the start of the—now missing—next file. It may also have to do with the ~* file, but I think it is probably the former. Is that the case? If so, I don't expect it to happen if the unflagged file is still physically present (I will confirm soon). Also, while I don't expect µTorrent to create a whole dedicated filesystem, is there any workarounds possible?

*UPDATE*

Yup, I just found the file (I hadn't deleted it after all—well, I knew I hadn't, I just couldn't figure out what the heck happened to it, or where it went). I put it back in the right directory and did another recheck, and they all came up 100% this time. So, it looks like it really is a file/piece boundry issue. Can a dev confirm?

Link to comment
Share on other sites

You can reproduce it like this:

(1) Download a torrent to 100% complete (all files 100%)

(2) Stop the torrent (and/or quit µTorrent)

(3) Move one file out of the directory

(4) (Run µTorrent)

(5) Mark the file you removed as "don't download"

(6) Do a recheck

Now, the file before the one that is now flagged to ignore will be listed as ~99% even though it is complete.

For example let's say you downloaded this torrent:

Filename - % - 1st piece - priority

---------------------------------------

File1.txt - 100% - 0 - normal

File2.txt - 100% - 101 - normal

File3.txt - 100% - 205 - normal

File4.txt - 100% - 298 - normal

File5.txt - 100% - 410 - normal

You then quit µTorrent, and move File5.txt to somewhere else, then rerun µTorrent and do this:

Filename - % - 1st piece - priority

---------------------------------------

File1.txt - 100% - 0 - normal

File2.txt - 100% - 101 - normal

File3.txt - 100% - 205 - normal

File4.txt - 100% - 298 - normal

File5.txt - 100% - 410 - don't download

Now you do a recheck and get this even though File4.txt is complete:

Filename - % - 1st piece - priority

---------------------------------------

File1.txt - 100% - 0 - normal

File2.txt - 100% - 101 - normal

File3.txt - 100% - 205 - normal

File4.txt - 99% - 298 - normal

File5.txt - 0% - 410 - don't download

Now move File5.txt back and do another recheck, and you'll get this:

Filename - % - 1st piece - priority

---------------------------------------

File1.txt - 100% - 0 - normal

File2.txt - 100% - 101 - normal

File3.txt - 100% - 205 - normal

File4.txt - 100% - 298 - normal

File5.txt - 100% - 410 - normal

I believe that it is because of piece/file boundaries. In this example, piece # 410 contains the end of File4.txt and the start of File5.txt. Therefore, when you move File5.txt and µTorrent checks piece # 410, even though File4.txt is still there and complete, the piece is not complete because the part of it that belongs to File5.txt is missing.

That is the most logical explanation that I can think of.

Link to comment
Share on other sites

I believe that it is because of piece/file boundaries.

Exactly right, and you can't do anything about it because of how multifile torrents are handled.

Great, thanks for confirming. Like I said, I don't expect µTorrent (or BitTorrent) to create it's own filesystem. :) I guess there isn't really a workaround other than putting the file back, but then again, at worst you would merely re-download the last piece (128K-4MB): a little waste, but not too big a deal.

Link to comment
Share on other sites

  • 1 year later...

i have a similar problem only i didnt download the whole file at all just a peace and now when rechecking it comes as 99.9%

and there is another file that is whole but it still reads as 99.9% but the size reads as identical even in utorrent, the first one is like in the exampe before

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...