Red Hat Bugzilla – Bug 445632
mount.ntfs-3g CPU usage is up while transmission is downloading
Last modified: 2008-05-20 16:54:22 EDT
Description of problem:
"mount.ntfs-3g" CPU usage is up while "transmission" is downloading
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. All last updates must be installed by "yum update".
2. Run "wget -c
3. Run "wget -c
4. Run Transmission and open these (steps 2-3) torrents for downloading to a big
busy NTFS partition (see attachment).
5. After CentOS-5.1-i386-LiveCD.torrent was ended and
CentOS-5.1-i386-bin-DVD.torrent is downloaded approximately for 25%, then CPU
FAN noise level is up, and CPU usage for "mount.ntfs-3g" process is 52-99%.
6. When PAUSE both of these torrents, "mount.ntfs-3g" process is returns to
normal low CPU usage.
Transmission Version is "Transmission 1.04 (4888)"
CPU is Intel Pentium 4 3.00GHz 1Mb L2 Cache Socket478
Created attachment 304832 [details]
logs of bug reproducing
Similar problem here (close to 100% CPU usage when downloading F9 via torrents).
When torrents stopped, CPU usage returns to normal (8-10%).
Roman: I have checked your logs. The problem is the third one from the list at
Btw, writing at many locations in the same large file at the same time (many
peers at the same time, etc) can be also a major factor for very high CPU
usage. NTFS-3G tries to counteract it but this can't be done when the disk is
highly fragmented which is usually always the case when the disk is close to
full (90% in your case).
I forgot to mention that you should __REALLY__ use at least 1.2506 instead of
I would tend to agree with your comments;
however I was using ntfs-3g-1.2506-1.fc9.i386, and the ntfs partition was empty
(far from the fragmentation stage).
I just formated that partition to fat32 and restarted the same torrents
resulting in NO high CPU usage (i.e. normal CPU load).
Just for my 2¢
Szabolcs, thank you!
Successfull update ntfs-3g to the latest 1.2506 version was fixed my problem.
After this update I was downloaded other torrents and run Transmission to
download to the same partition with normal CPU usage (mount.ntfs-3g usage less
2all: Can I close bug status?
I replied to Roman. There are over nine trillion reasons for high CPU usage and
http://ntfs-3g.org/support.html#cpu100 lists only the most common ones.
Roman provided quite a lot of very useful debug logs (bug submission and comment
#1) which helped to analyze the problem. You provided none, so it's not possible
to tell what is your problem.
One thing is sure. Unlike NTFS, FAT doesn't support sparse files so data
allocation is either simple sequential or the file is preallocated which
completely avoids the problem I described. Some torrent clients detect file
system capabilities and work differently. I also bet that you can't save bigger
than 4 GB files on FAT ;-)
Sorry for the delay in replying (I did reply but was not logged-in I guess!! So
much for the new guy on Bugzilla).
I thank you for your comments, and will provide more solid/factual information
next time on Bugzilla.
@Roman, go ahead and change bug status to closed if OK with other participants.