On a recent (3 weeks old) FreeBSD 9.0 installation I set up kTorrent to save data onto a ZFS mirror using WD EARS + Intel SSD cache. Dedup is sha256,verify.

"Data checking after downloading" is turned on as always (for me).

It turned out that most of the torrents I downloaded in the last weeks (since I installed the system) have failed chunks. Too bad that if I re-check data and download the missing parts again they still can have failed parts after I reboot the system. Usually between 1 and 10 parts are failed but one torrent has 150 failed parts.

The failed torrents are from different trackers and they are not related to each other.

I never experienced this on Gentoo + ZFS + kTorrent, however I used kTorrent rarely. To be honest I can recall some errors with kTorrent-downloaded movies from the last year but I didn't double-check them.

As for ruling out memory errors I ran prime95 for 7 hours in different modes and the ram is fine. Router also shouldn't be a problem since "data checking after downloading" is turned on. Also note that at least one double-checked torrent became corrupted again after a reboot.

To be absolutelly sure I also have VirtualBox + Windows + uTorrent on the very same system and it saves onto the very same ZFS filesystem (with samba). It has 2200+ torrents.

I checked all the torrents I downloaded with uTorrent in the last 6 days (average size is 600Mb, number of torrents is 40+). They are 100% fine even after several dirty shutdown of the VirtualBox machine during the last couple of days.

I also have some torrents in the kTorrent data folder which were downloaded not with kTorrent but with uTorrent for linux. Then I added the torrent files to kTorrent and did re-check. Without downloading their data again. These torrents all have 0 failed parts no matter how many times I check them.

Only the torrents downloaded with kTorrent have failed parts as far as I can tell.

These errors are real. For example they can be seen in a movie. (Re-checking fixed then so it is not the torrent which has the errors).

'zfs status' also shows zero errors on the pool.

FreeBSD 9.0-RC3 FreeBSD 9.0-RC3 #0

kTorrent is 4.1.3, KDE 4.7.3, everything is compiled from source. I checked some extra options including "using threads" for several ports.

I can see the check failing due to running out of file descriptors, but that shouldn't corrupt any data.

George wrote:I can see the check failing due to running out of file descriptors, but that shouldn't corrupt any data.

Unfortunately the same torrent downloaded with KTorrent and Transmission differ.

Also the first completed version downloaded with KTorrent and the "repaired" (re-checked and reloaded missing data with KTorrent) also differ.

I have backup of the first version so I could diff them.

The system has:

kern.maxfiles=204800
kern.maxfilesperproc=200000
kern.maxvnodes=200000

I'm gonna install a virtual machine with freebsd and zfs and see what is going on.