Samba slows down shortly after restart of service
 

Hi,

I am using Ubuntu 9.04 Server Edition (with just Gnome-core etc. installed) on a Dell Studio XPS435MT (Core I7 processor, 3GB memory, 3ware RAID controller, two 750GB Western Digital Disk drives). We run a workgroup of about 7 Windows XP clients (running SP2) & use SAMBA for networking.

In Windows XP, we are all logged on to the alpha domain. Our WINS server points to the IP address of the server, and the server's "hosts" file contains the 'names' & address of each of the workstations. The LMHOSTS file on each XP workstation points to the server, and netbios is enabled.

Immediately after restarting SAMBA service on the Linux server:
* Creating a new folder within the share (from the XP client) is very quick / immediate;
* Running some of our database reports are very quick (one reference report takes 6-sec to complete)
* Large file transfer (524MB) takes ~18-sec from server to XP client

After waiting a few minutes:
* Creating a new folder: When renaming from "New Folder", it takes about 8-9 sec to finish creating the folder
* Database report: takes about 30-sec
* Large file transfer (524MB) takes same ~18-sec from server to XP client (unaffected)

The above action is repeatable (tried restarting SAMBA 3-times, same result).

I am puzzled by what is going on. Why do some network functions slow down after a few minutes of SAMBA restart?

Below is my SMB.CONF file. I would appreciate any feedback. FYI... I am not totally a newbie, but I cannot claim to be a Linux expert by any means.
---- SMB.CONF ----
[global]

workgroup = alpha
server string = Den_samba
wins support = yes
netbios name = epsilon
dns proxy = no
name resolve order = wins lmhosts bcast host
log file = /var/log/samba/log.%m
max log size = 1000
syslog = 0
panic action = /usr/share/samba/panic-action %d

security = user
os level = 64
domain master = yes
preferred master = yes
domain logons = yes

printing = cups
printcap name = cups
cups options = raw

SO_RCVBUF=16384 SO_SNDBUF=16384
socket options = TCP_NODELAY IPTOS_LOWDELAY

#======================= Share Definitions
[netlogon]
comment = Windows Network Logon Service
path = /home/netlogon
writeable = yes
guest ok = yes
share modes = no

[Main]
path = /home/localdata
public = yes
writeable = yes
inherit permissions = yes
oplocks = no
create mask = 2777
force create mode = 2777
directory mask = 2777
force directory mode = 2777

[database]
path = /home/database
public = yes
writeable = yes
inherit permissions = yes
oplocks = no
create mask = 2777
force create mode = 2777
directory mask = 2777
force directory mode = 2777

[accounting]
path = /home/accounting
public = yes
writeable = yes
force create mode = 2777
force directory mode = 2777
oplocks = no
inherit permissions = yes
create mask = 2777
directory mask = 2777

[Archive]
path = /home/archives
public = yes
writeable = yes
inherit permissions = yes
create mask = 2777
force create mode = 2777
directory mask = 2777
force directory mode = 2777

[printers]
comment = All Printers
path = /var/spool/samba
guest ok = Yes
printable = Yes
use client driver = Yes
browseable = No
public = yes