Jump to content

uTorrent and sparse file attribute


myriaxis

Recommended Posts

Hi,

I've been using uTorrent on Windows for quite a while and I just noticed a few days ago that when a download is completed, the resulting file (or files) has (or have) the SparseFile attribute set (P). This behavior seems to have started around August 2015 based on a comparison of different downloads made over the past year. That SparseFile attribute is mostly transparent, but it prevents .iso to be mounted using Windows Explorer.

I'm using Windows 8.1 Pro and the HD is NTFS formatted. I can use fsutil to reset the sparse flag, but it doesn't work on all files. The safest workaround is to copy the files, but it takes time and HD space.

I'm not suggesting there is a bug in uTorrent, but what can explain this behavior? I understand uTorrent uses sparse files to help download speed and limit HD space usage during download, but when the download is complete, shouldn't the SparseFile attribute flag be reset?

Link to comment
Share on other sites

Maybe it is related to Windows Explorer, but I'm skeptical. uTorrent creates the file as sparse at the beginning of the download. How would Windows Explorer know when to clear the SparseFile attribute? Only uTorrent knows when the download is complete. So it is logical to assume that uTorrent should clear the SparseFile attribute once the download is complete. Maybe uTorrent already does that, but for some reason it doesn't work on my rig.

Can we confirm that uTorrent does clear the SparseFile attribute upon download completion? Is there a way for me to debug this problem on my rig since I can reproduce it ad nauseam?

Thanks.

Link to comment
Share on other sites

If a file is tagged as sparse, then for the OS and other apps it means it's not complete. Obviously, you can still read the file. If the app doesn't care about the sparse attribute, then you're OK. So far, the only real problem I've noticed is that Windows refuses to mount .iso file when the SparseFile attribute is set. As I said, the workaround is to create a copy of the download file. But this is time consuming. I'd rather try to fix the SparseFile attribute once the download is complete.

So, can we confirm that uTorrent does clear the SparseFile attribute upon download completion? Is there a way for me to debug this problem on my rig?

Thanks.

Link to comment
Share on other sites

Archived

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

×
×
  • Create New...