[Samba] excessive TCP retransmissions with samba 3.0, slow file opening

[Jeremy Anderson]

Hello all!

I've got a Fedora Core 3 box running Samba 3.0.8.
It serves a variety of roles, including mail server and samba server.
The mail server is quite fast, but the smb server generates lots and lots of TCP retransmissions (as seen in ethereal).  The general consensus is that this is new in the last few weeks.  One user has been reporting speed problems for some time, but no metrics were ever gathered.

I've tried replacing the NIC, but the problem follows.  This is a small network, with two 100mbit hubs, and windows 2000 on all the clients.

I want to suspect hardware, but flood pings from a linux box put on the network never report dropped packets.  

All hosts are listed in DNS, and reverse DNS lookup is successful.  I've also configured samba to pass WINS requests on to DNS.

I'm absolutely stumped.  I don't see the retransmissions with anything on the network except SMB-related TCP traffic.  

I don't see anything peculiar in  /var/log/messages or the smbd.log file.  nmbd is running just fine.

Any assistance is greatly, greatly appreciated.

Jeremy
-- 
Jeremy Anderson		jeremy (at) angelar.com	
http://www.angelar.com/~jeremy