samba - Sep 2007 - Very slow execution of programs from a SAMBA share

Hi.

I've run into a significant performance problem,
where Samba shares are fine except for programs executed
from the shares, which take about 100x longer to launch
than expected.


Copying local Windows directories with large files to the
Samba share is getting 30 Mbytes/second. However, trying 
to run programs from the same samba share is taking 30 seconds
to 5 minutes to launch the application (compared to sub-second
launch time from shares from Windows XP 64 Pro systems for the
same programs).


I'm trying to set up Samba 3.0.24 under Ubuntu 7.04 as WINS master
workgroup (not domain) server, to share to a dozen systems running
Windows XP Pro 64 SP2. Network switch is a Netgear 16 port Gigabit switch.
The ADSL modem is acting as DCHP / DNS server for the network.
For now firewalls are disabled on the Ubuntu server. 
Disabling firewalls on the XP Pro 64 clients is making no difference.


I've tried many different things, and nothing seems to make any
difference.

I'm wondering if there is a SAMBA / XP 64 bit client problem,
or if the problem is somehow related to the switch, because NBTSTAT
is reporting a "MAC Address = 00-00-00-00-00-00" for the
Samba server.


I can't see any obvious problems. I can browse the samba server.
The shares are visible and having no access problems. Other applications
have no problem with UDP broadcasts working across the switch.


The show-stopper problem is that application load time
is horrible if an application is run from the Samba share
(around 100x slower than it should be).


The clients are standard XP Pro 64 with latest SP2 patches.  They
have no problem running applications from another XP Pro share.


Any help or hints would be greatly appreciated.

Output from nbtstat looks fine except for the MAC address:

---------------------------
C:\>nbtstat -a snsix

Local Area Connection 3:
Node IpAddress: [10.1.1.7] Scope Id: []

           NetBIOS Remote Machine Name Table

       Name               Type         Status
    ---------------------------------------------
    SNSIX          <00>  UNIQUE      Registered
    SNSIX          <03>  UNIQUE      Registered
    SNSIX          <20>  UNIQUE      Registered
    ..__MSBROWSE__.<01>  GROUP       Registered
    SNS            <1D>  UNIQUE      Registered
    SNS            <1B>  UNIQUE      Registered
    SNS            <1E>  GROUP       Registered
    SNS            <00>  GROUP       Registered

    MAC Address = 00-00-00-00-00-00
-----------------------------


The smb.conf file is pretty standard, unless I've missed something obvious:


----------  smb.conf ---------------
#
# Samba for Linux
#

[global]
   workgroup = SNS
   netbios name = SNSIX
   server string = %h

   wins support = yes
   name resolve order = wins lmhosts hosts bcast
   domain master = yes
   local master = yes
   preferred master = yes
   os level = 35
   dns proxy = no

   security = user
   encrypt passwords = true

   hosts allow = 10.1.1.0/255.255.255.0 127.0.0.1 EXCEPT 10.1.1.1
   hosts deny = ALL

   socket options = TCP_NODELAY IPTOS_LOWDELAY

# Logs
   log file = /var/log/samba/log.%m
   max log size = 1000
   syslog = 0
   panic action = /usr/share/samba/panic-action %d

# shares
[data]
    path = /mnt/data
    writable = yes
    user = sns
--------------------------------------



Thanks in advance for any suggestions on how to resolve
this problem. I want to move our servers over to Samba/Linux,
but can't until this problem is resolved.


Stuart

> You could try setting some of the oplock options. I think "fake
oplocks = yes" on the
> application share could significantly increase the performance when
executing.
?der,

Thanks for your response.

The slow share problem turned out to be a Samba/Ubuntu 7.04 problem with some
NICs -
symptoms are slow access *unless* several clients are accessing the same
share at the same time (or xfer of large files).  Once you know what to
search for, it turns out to be a very common issue for many people.

Weird, and took a long time to resolve.  I swapped NICs in the end.

I then ran into another problem where Samba refused to be come master
domain server because it thought there was already another, but
non-existant server (which turned out to be Samba, from when the
server was using a different IP address).

Again much searching, to find that deleting /var/libs/samba/wins.dat and
restarting Samba fixed that problem.  Bottom line is that moving Samba
to a new IP causes issues that can only be resolved by deleting wins.dat.



I'm now trying to work out why Samba shares die whenever clients running
DHCP get their IP lease renewed.   Another show-stopper problem. If I
don't solve it today I'll go back to Windows Server 2003.  Which is a
shame,
but I can't afford to spend much more time on this.


Samba looks great, and I appreciate the amount of time it must have taken
to decode the CIFS protocols.  But what is a bit worrying is that getting
Samba to run in a pretty standard environment is turning out to be a huge
nightmare, which would not encourage users to switch from Windows servers
to Samba.  The frustrating thing is that many of these problems look to
be common issues that are likely to be common on small Windows networks
wanting to use Samba.

Regards,

Stuart