[Samba] "Oplock" error messages with samba on Linux

[Amit_Bhutani at Dell.com]

TEST: 
=====
SAMBA STRESS OVER GIGABIT NETWORK: This is a simple
Read/Write/Compare/Delete kind of test over the network via Samba. Multiple
clients with multiple threads try to read/write/compare/delete(in a loop) a
finite sized file (64K block size) over samba for a prolonged period of time
in an effort to stress test the server. 

SERVER SIDE CONFIG:
===================
ARCH: x86 
OS: RHL AS 2.1 
KERNEL: 2.4.9-e.3smp
SAMBA: 2.2.7-1.21as.i386.rpm (also tried RH AS2.1 stock version:
2.2.1a-4.i386.rpm)
NIC: 2 ONBOARD GIG BCM5703(COPPER)ON A STATIC GEC TRUNK
RAM: 512 MB 
CPU: Dual 2.66GHz CPU with HT ON (tried several different speed CPU's: 2.2,
2.4, 3.06 etc)
SWAP: 2 GB
SCSI/RAID: Able to reproduce this on SCSI as well as RAID 0 (not tried other
RAID configs)

CLIENT SIDE CONFIG:
===================
SAMBA CLIENTS: Windows only (tried both NT4 and W2K). Please note that there
are *no* Linux clients trying to access the samba share. The clients are all
Windows and are all installed from one common image.

DESCRIPTION OF FAILURES:
========================
The Stress Test Controller starts to show some Read/Write/Compare failures
anywhere from a 30 mins up to a 24 hour period into the test. These failures
continue to occur and eventually the server "locks up". Tried to enable
"nmi_watchdog" with serial console. No OOPS capture yet. I also tried
raising the samba debug level (went up to 3) , printk level raised to "7 4 1
7", SysRq enabled etc. None of the information I have captured so far gives
me any definite theory on why this is happening. What I do notice is that in
almost all the failures, the samba logs have references to "oplocks". Any
body has any ideas why this could be happening ? Any ideas for what I can do
further to troubleshoot. I have tried various other things that I have not
posted with this message to try and keep this post readable. Posted below
are a sample smbd.log, <samba_client_name>.log and my smb.conf file from one
of the recent failures. Any suggestions would be helpful.

/var/log/smbd.log:
==================
[2003/03/12 04:02:03, 0] smbd/server.c:open_sockets(238)
Got SIGHUP

/var/log/samba/samba_client1.log:
=================================
[2003/03/11 10:04:07, 0] passdb/pdb_smbpasswd.c:pdb_getsampwnam(1369)
  unable to open passdb database.
[2003/03/12 03:33:49, 0] smbd/oplock.c:oplock_break(790)
  oplock_break: end of file from client
  oplock_break failed for file ZEUS05/ZEUS05_0.dat (dev = 811, inode =
131074, file_id = 5907).
[2003/03/12 03:33:49, 0] smbd/oplock.c:oplock_break(878)
  oplock_break: client failure in break - shutting down this smbd.
[2003/03/12 03:34:15, 0] smbd/oplock.c:request_oplock_break(1008)
  request_oplock_break: no response received to oplock break request to pid
2482 on port 32793 for dev = 811, inode = 131074, file_id = 5907

/etc/samba/smb.conf:
====================
[global]
netbios name = box_400
server string = Samba Server
security = SHARE
encrypt passwords = Yes
log file = /var/log/samba/%m.log
max log size = 0
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
dns proxy = No
printing = lprng
wins support = yes

[homes]
        comment = Home Directories
        writeable = Yes
        browseable = No

[printers]
        comment = All Printers
        path = /var/spool/samba
        printable = Yes
        browseable = No

[share]
        path = /stress
        writeable = Yes
        guest ok = Yes

[web]
	path = /var/www/html
	writeable = Yes
	guest ok = Yes

- Amit Bhutani