Save to network drive stops lan connection cable unplugged

[BeowulfNode]

Problem Info

I've been having the problem of whenever I am downloading or seeding a torrent directly from a network drive there is are massive lan traffic spikes of 100% of 1gbps then after a few of those something tells my lan that the cable is unplugged, the torrents stop and then the network usually fixes itself. If not a disable and re-enable the lan adapter fixes the lan.

I recently moved from an older version of utorrent on Vista 64bit which was able to do this fine to uTorrent 2.2.1 build 25249 on Win7 64bit Pro with SP1 that is now showing this problem. One other note Vista had a major problem with using the full 1gbps lan bandwidth where Win7 can max out the lan.

I had this with both realtek lan driver v7.028 and the newest v7.038.0113.2011 for my Gigabyte GA-EP35c-DS3R motherboard.

The network drive is mapped to a samba share on a ubuntu server 10.10 computer as a nas with default samba options with all required security options for full read/write access. I don't know how much of a difference it makes but the ubuntu server is set up with zfs-fuse raidz1 with 3 sata II drives which when combined in this fashion can provide read speeds to saturate the 1gbps lan. Writing is slower but can still maintain over 20MB/s with drag and drop files from single sata II local drive to the nas.

Saving directly to a local disk works fine for me with with the above setup going at 1.7MB/s down and 55kB/s up with over 100 simultaneous connections.

Stuff I've Tried that Hasn't Worked

I've tried reducing the bandwidth in utorrent to 40 kB/s both in and out

I've tried reducing the number of simultaneous connections to 10

I've disabled the windows firewall and there is no AV or firewall software on this PC yet as it is a fairly new install of windows. (yes all the windows updates are done)

I've tried various combinations of uTorrents disk cache options, such as cache read only, write only, none, use windows.

My Thoughts

While I've not looked in to the details of Win7 <--> ubuntu server 10.10 samba communications I'm guessing there's a problem like too many too large packets in a row causes either my network drive or the switch to have a temporary heart attack. Anyone have any suggestions

Your Thoughts...?

I've read that this situation isn't supported by some on this forum, but I would like to find out other peoples experiences

[DreadWingKnight]

The long and short of it is that you're either overloading the network card or switch if you're getting the cable unplugged message on your windows machine. Given that the LAN connection doesn't always come back immediately, I'd say it's more likely the network adapter drivers.

But again, direct saving of torrent downloads over a network cause a multitude of problems like this.

[BeowulfNode]

Yes there does seem to be an overload but I'd like to identify what is going on and hopefully do something about it. It does not seem to be the amount of internet traffic as the nic, nas, and nas hdds can handle a sustained 30 times the max internet bandwidth I have without a problem. However there is still the lan traffic spike regardless of how slow I make utorrent go.

Oh and I only get this spike while utorrent is saving/seeding to/from a network drive, no other time does this happen. Also the write spike of a completed piece is a relatively small spike of traffic that seems to happen at an unrelated time to the lan breaking spikes.

Looking a bit closer at the traffic spike in performance monitor I see that the spikes reach

* Received: 1,437,725,496 Bytes/second (that's not bits)

* Sent: 719,983,749 Bytes/second (again that's not bits)

and both Tx and Rx happen on the same sampling second.

This is a lot more than the supposed maximum theoretical speed of a full duplex 1gbps lan and may actually be an incorrectly reported value and be a symptom rather than the problem. But until I can see otherwise I'm going to believe there is a large traffic spike.

If I slow down utorrent to a tiny 8kBytes/s each way these spikes are still as large but less often. This is why I thought it had something to do with cache.

Any ideas on what to check next?

[BeowulfNode]

I finally fixed the problem

Well Realtek did, by finally fixing their drivers in v7.046 on 21 jun 2011

On my Gigabyte GA-EP35C-DS3R motherboard onboard nic which is a Realtek 8168

ven 10ec

dev 8168

subsys E0001458

rev 01

PCI\VEN_10EC&DEV_8168&SUBSYS_E0001458&REV_01

I now only get the much smaller traffic spikes as utorrent reads or writes a data block from the nas. These smaller spikes do not affect utorrent's performance

Note

Realtek seem to produce a single driver file for all their models like nvidia does, just a few different ones for different OS's. So if you have a Realtek nic this driver update may help you too.