CentOS - Mar 2010 - NFS freeze when transmitting big files

Hi,

I have one old spare PC, a PIII with 128 MB RAM, that I use as a spare 
file server. I have a headless CentOS 5 install on it, and a 2 terabyte 
external USB harddisk. The machine is in my basement (because it's quite 
loud), and I'm using what's called "CPL" here (Courant
Porteur), which
is basically Ethernet over 220V power lines. It's much slower than 
normally cabled Ethernet, but it works OK.

I setup an NFS server on this machine, with the big 2TB storage on the 
external disk. On the first floor, on my main PC, I setup a consistent 
mounting of the NFS shares in /etc/fstab, and it works.

Now here's the problem. Some of the files are quite big, usually movie 
files that can make up to 4 GB. More often than not, when I cut/paste 
such a file from my local harddisk to the server, it's quite slow 
(understandably, due to the slow CPL connection), but then the operation 
freezes in the middle, the cursor is unresponsive, even 
[Ctrl+Alt+Backspace] doesn't work, and I have to do a hard reboot.

Now I wonder what this phenomenon can be due to. Some strange bottleneck 
effect due to either lack of RAM to the server or the slow network or both?

Any ideas?

Niki

On Tue, 2010-03-30 at 12:27 +0200, Niki Kovacs wrote:
> Hi,
> 
> I have one old spare PC, a PIII with 128 MB RAM, that I use as a spare 
> file server. I have a headless CentOS 5 install on it, and a 2 terabyte 
> external USB harddisk. 
---
This may help help you I have the same problem.

First to rule out the USB Drive copy file on the server machine itself
from like a dvd rom to the USB Drive in order to check out how it is
working,

Try this go directly to the Mount Folder of your NFS Share and open it
up then copy and paste a file into it.  Don't do a browse network to
access the nfs share.  You want the hard mounted nfs share.

You should have better success with another 128MB of RAM..

Case point I have one also a P3 450 256MB RAM CentOS 5.4 here at home
using samba + clam av and large files make me have to hard mount the
directory to paste to the server.  I run no GUI either on it so you may
want to get rid of X and Gnome.  Mine I run in, run level 3 so no gui
here because it was painfully slow.

John