samba - Mar 2012 - Samba and admin users performance

Hello,

I have a performance problem when I don't connect using root and/or a user
in the "admin users".
Configuration:
Samba 3.5.11 running on SLES11SP1. The share exported is on a GPFS
filesystem and the GPFS vfs object is loaded(not loading it doesn't change
the described behaviour)
clients: Windows 7 and Windows 2008R2 all at latest update level.

[testshare]
        comment = testshare
        path = /testfs1/testshare
        read only = no
        force create mode = 0666
        force directory mode = 0777
        force security mode = 0666
        force directory security mode = 0777
        admin users = testuser


If I connect using a user other than testuser, I get ~8 MB/s from the
clients, and if I look at a trace, I can see that all read operations are
in 4K blocks(Read AndX Request/Response). If I connect using root or
testuser(which is in the admin users), I get 50MB/s and samba goes up to
60KB blocks when reading. Also during the negotiation, I can clearly see
that "Max Buffer: 0" is set in the "Session Setup AndX Request,
NTLMSSP_NEGOTIATE sent by the client, while this is 16644 when connecting
as root/testuser.
When switching to "security = share" and using guest access, I can see
the
same behaviour. Setting force user/group to root gives good performance,
setting it to something else kills performance.

Is this expected, or am I missing something?

Best regards,
Stijn

On Tue, Mar 27, 2012 at 09:13:44AM +0200, Stijn De Smet
wrote:
> Hello,
> 
> I have a performance problem when I don't connect using root and/or a
user
> in the "admin users".
> Configuration:
> Samba 3.5.11 running on SLES11SP1. The share exported is on a GPFS
> filesystem and the GPFS vfs object is loaded(not loading it doesn't
change
> the described behaviour)
> clients: Windows 7 and Windows 2008R2 all at latest update level.
> 
> [testshare]
>         comment = testshare
>         path = /testfs1/testshare
>         read only = no
>         force create mode = 0666
>         force directory mode = 0777
>         force security mode = 0666
>         force directory security mode = 0777
>         admin users = testuser
> 
> 
> If I connect using a user other than testuser, I get ~8 MB/s from the
> clients, and if I look at a trace, I can see that all read operations are
> in 4K blocks(Read AndX Request/Response). If I connect using root or
> testuser(which is in the admin users), I get 50MB/s and samba goes up to
> 60KB blocks when reading. Also during the negotiation, I can clearly see
> that "Max Buffer: 0" is set in the "Session Setup AndX
Request,
> NTLMSSP_NEGOTIATE sent by the client, while this is 16644 when connecting
> as root/testuser.
> When switching to "security = share" and using guest access, I
can see the
> same behaviour. Setting force user/group to root gives good performance,
> setting it to something else kills performance.
> 
> Is this expected, or am I missing something?
No it's not expected. Something else is going on here...