Weird disk cache problem :(

[gueriLLaPunK]

So I've been searching the ends of the interweb for an answer to my problem. It seems to only affect my gigabit servers with uTorrent on them. Debian, no problem, but the problem I have is on both Windows 2003 64bit and Windows 2008 Web.

Basically, uTorrent is not writing to the disk at ALL. It writes to the cache, but writes super slow, or none at all to the disk. I've tried messing around with different settings and haven't found a solution. This problem is on two separate servers at two different data centers. I'm hoping some Window experts can help me, because I think it might be a security issue? I don't know, but it seems to has to do with Windows and uTorrent.I've already done the increase disk cache, disable windows write cache, etc, but nothing works. I even disabled caching all together and nothing. Here is the screenshoot:

http://i41.tinypic.com/ayrk3l.png

Click on this link to view full size:

http://i41.tinypic.com/ayrk3l.png

On this same server, I had no problems with Debian + lxde + WINE + uTorrent. So that narrows it down further to being just Windows and uTorrent. Any help would be greatly appreciated!

Take care

[Tokeman]

How long are you waiting before you assume its not writing? On every windows box I have (not server) larger files especially, it will only write to the cache until it has reserved the full amount of space required for the file. In this case, its quite a large file, and that could take a while. For example, on a 4GB dvdr, when I start a DL, the actual files don't start writing to the disk right when it starts dling, it takes about 4-10 minutes depending on what other apps are accessing my drive at that time.

[gueriLLaPunK]

How long are you waiting before you assume its not writing? On every windows box I have (not server) larger files especially, it will only write to the cache until it has reserved the full amount of space required for the file. In this case, its quite a large file, and that could take a while. For example, on a 4GB dvdr, when I start a DL, the actual files don't start writing to the disk right when it starts dling, it takes about 4-10 minutes depending on what other apps are accessing my drive at that time.

Because I have a 100mbit Windows 2k3 box and I don't have this problem. If I let uTorrent continue to run, it will lock up cuz the cache will be over 2GB. I don't understand why this is happening on two different servers. I tried Vuze and I get disk cache errors. Deluge seems to work ok, but I only get 16MB/sec. I've speed tested the hard drives and they are capable of 60-100MB/sec read and 50MB/sec write.

What should I do to isolate the problem?

Thanks for the help.

[Tokeman]

Does it happen on smaller files or just large ones?

[gueriLLaPunK]

Any size file. At any speed. I could download at 1MB/sec and the cache will fill up and not write to disk.

[Tokeman]

Are the two problomatic servers running any similar hardware? Same hardware raid or anything like that? Could be an odd driver issue, but I've never seen anything like that before...

Do you have the same problem outside torrents? Can you download a big ISO through IE for example, or does that lock up the system as well?

[gueriLLaPunK]

Are the two problomatic servers running any similar hardware? Same hardware raid or anything like that? Could be an odd driver issue, but I've never seen anything like that before...

Do you have the same problem outside torrents? Can you download a big ISO through IE for example, or does that lock up the system as well?


One server is a Quad Xenon with 8GB RAM and Windows 2003 64bit. Hardware RAID 1. It has 2x750GB

The other is a Dual Core Duo2 with 4GB of RAM and Windows 2008 Web with Hardware RAID 0. This one has 2x500GB

I downloaded some service packs from Microsoft on my Dual Core server with Windows 2008. I was getting a steady 1MB/sec and it wasn't locking up. I DLed a pack that was 220MB and one that was over 400MB.

I've posted this problem on uTorrent's forums but haven't gotten a response. I see the RAID controller on my Dual Core server and seems to be working fine.

[Tokeman]

Can you try to dl a bigger file, one over your cache size through FF or IE over HTTP or FTP? Maybe a SUSE image or something like that? Just wondering if its protocol related or OS related.

[gueriLLaPunK]

Can you try to dl a bigger file, one over your cache size through FF or IE over HTTP or FTP? Maybe a SUSE image or something like that? Just wondering if its protocol related or OS related.

I'm downloading openSUSE thats over 4GB and its only going at 30+KB/sec

Im also downloading Linus SUSE enterprise which is 3.6GB and thats going over 16MB/sec.

EDIT: I started two downloads, one 3.6GB and one 2.5GB and each were doing 16MB/sec each from the Linux SUSE (novell) website.

EDIT AGAIN: Ok... so I installed Deluge and I can DL torrents at around 16MB/sec and upload around 10MB/sec. This is working on both servers. Hmm... but when I load up uTorrent, it downloads much much faster, but the disk statistics show it as writing to the cache only and not to the disk.

[Tokeman]

Update when the cache fills or it starts writing :)

[gueriLLaPunK]

Update when the cache fills or it starts writing :)

Deluge seems to be working fine. Weird. I'm doing 20MB upload on the quad xenon and 13ish on the dual core. Still, not as fast as uTorrent, but OK in the mean time.

As I said before, the Quad Xenon had Debian + lxde + WINE + uTorrent and worked great! Over 55MB/sec. So... I'm wondering why it doesn't write to the disk, even at low speeds.

I also have a 100mbit Windows 2003 server that downloads and uploads around 12MB/sec with no write issues. The difference with that server, it isn't with any RAID, just a single 250GB hard drive.

[Tokeman]

sounds like a hardware/driver issue with the way the program is interacting with the cache. I know windows 2003 has a disk cache manager, have you tried playing with that at all?

[gueriLLaPunK]

sounds like a hardware/driver issue with the way the program is interacting with the cache. I know windows 2003 has a disk cache manager, have you tried playing with that at all?

No idea. Where do I look for that?

BTW, thanks for all the help. I've been trying to figure this out for days now :D