file-skipping and pre-allocate

[Guest]

I have just installed 1.1.2 and im trying to download 1 file from a batch with 10 files, the problem is that when i choose skip on the files that i don't want to download and press "Start", uTorrent ignores the skip and tries to pre-allocate all the files on the torrent (Wich i don't have space for) and then refuses to continue due insufficent diskspace.

[Guest]

I disabled the pre-allocate option and it seems like that option always forces to allocate *all* files available in the torrent. And when disabled it only allocates the non-skipped files. In my opinion you should try to explain this a bit better because it can be missunderstood easily. For example the most torrent programs don't pre-allocate files by default as uTorrent does.

[Guest]

... Hello again

Last post hopefully:

If each chunk in the torrent is 4MB and the file i want to download is 100kb uTorrent will try to download 2 files (in my case) first the SFV file that i want to download (100kb~) and one avi wich is 150MB.

This is probably because something in the allocate algorithm is weird

[vurlix]

This is because µTorrent always downloads full pieces, and the file you wanted shared a piece of data with another file. µTorrent always allocates the entire file regardless of how much data was downloaded from it. This means that, for example, if a torrent contained 1000 small files and they all shared the same piece, they would all be downloaded even if you selected "Do not download" on all but one file.

[Guest]

So are you going to do something about it?

In my opinion you shoud

[Smoovious]

So are you going to do something about it?

In my opinion you shoud

No he shouldn't. Torrents don't work like that. You either download a chunk or you don't. It is all chunks to torrents.

If you wanna download smaller pieces, then ya gotta take it up with the people who are creating the torrents to begin with, and ask them to use smaller chunks. You'll still download partials of nearby files, but you won't download as much of them.

What you ask, just isn't very feasable with the way torrents work.

-- Smoovious

[vithos]

I think this is actually something that could be improved. I don't mind uTorrent allocating files that share pieces with files I have not skipped, but what seems to happen is that every file in the torrent gets allocated (if pre-allocate is enabled) even if every piece that these fails consist of is set to skip. For example, say there's a 1GB torrent, with 1024 1MB files, and the piece size is set to 768KB. If I have pre-allocation disabled and skip every file but the first file, then the first 2 files will be created during the download process. However if I have pre-allocation enabled, uTorrent will pre-allocate all 1024 files. This is not just because uTorrent always downloads full pieces.

From the perspective of someone without access to the uTorrent source code, it seems like it would be pretty simple to add a test during the pre-allocation loop to determine whether the files being pre-allocated have any pieces not set to skip. But maybe I'm wrong.

By the way, this is with 1.1.3 on Windows XP/NTFS.

Either way, thanks for this great client. For now I will leave pre-allocation disabled and perform filesystem defragmentation occasionally.

[toe_cutter]

Sorry for bumping an old thread :oops:

As i have understood it, the non-wanted file of the 2 files that share pieces are stored in the partfile-file (lot of files ).

So why shouldnt uTorrent be able to not allocate the disk space of the file that is skipped? (Tho i dont know how the other programs do it, because they seemingly dont have the partfile-file)

Every other torrent-program can do it, and its very useful. One doesnt have to free up space for that file that should be skipped in the first place, and you dont have to manually delete the file when the task has finally been deleted (unless you unrar the file needed and do 'Delete torrent+data' of course, or does that delete the whole folder with unrared files?).

Well, my two cents.

If its been taken up more indepth somewhere, i apologize for my lazyness of not using the search button. I will use it more in the future.

[vithos]

µTorrent must receive and keep the extra data from parts split between files because peers do not know which files another peer has, they only know which pieces the other peers have (I believe this part of the protocol works by transferring a bitmask between peers). In these more recent releases progress is being made towards more sensible behavior skipped files. In fact, it's perfect as far as I know now as long as you don't pre-allocate the files.

There is still room for improvement in that area because with pre-allocate enabled µTorrent does not use the partfile, and still allocates all files no matter what, even if you tell it to skip every file. Pre-allocate mode should behave the same way as non-pre-allocate mode, other than the files are zeroed to the length described by the .torrent. Hopefully we'll see this happen soon, so I can turn pre-allocate back on and fragment my disk less

[MustNotSleep]

you can give explanations all you want on why it behaves like it does, the point is this works in every other client i've used.

so please, fix this feature.

[MechR]

It sounds like it works the same as Azureus. If you choose one file from a torrent, you usually end up with full blanks of the adjacent files because the end pieces don't line up with the file. The only client I've seen that doesn't create unwanted blanks is Bitcomet.

[Greek]

yes, fix it please.

[Firon]

Don't use pre-allocate.

There's no reason for you to use it if you need all this stuff. It doesn't really decrease fragmentation.