samba - Apr 2010 - samba server file read size limit of 64MB for HDF files

Sorry if that's a vague subject, but this problem is a little weird and
I'm just wondering if there are any suggestions out there.

We've got a Samba server (3.0.23) running on a CentOS 5.3 server offering up
a data share of 7TB on an XFS filesystem. The authentication all happens through
a Samba PDC with an LDAP backend all on a different server. The system in
question is just a domain member fileserver.

On the data share are several HDF files that we try to read into a couple of
different applications on XP. I'm using the Compaq Array Visualizer just to
look at them. The files on the server are owned by root, and world
read/writable. As a regular user on the XP client, if I look at one of the files
that's ~30MB in size, I'm presented with all the numbers I expect to
see. If I look at a file that's larger than 64MB (80MB for the specific ones
I was testing, but we've found the problem after 64MB in size) I no longer
see the numbers that I would expect...it's all zeroed out at the beginning.

If I copy the 80MB HDF to my local XP workstation, it works fine, so it's
not a corrupted file or anything.

The weird part is that if I go onto the linux server and change the ownership of
the file to my regular user account, it all works fine...I can read the 80MB
file through samba and see all the numbers I should...but no other users can. If
I change the ownership to someone else, they can then see it all, and I
can't again.

At one point all of these files were hosted from a Windows 2008 Server, and
never experienced these problems, only after the move to the Samba server.

The fact that anything smaller than 64MB works, starts to sound like a possible
setting that I can change.

Unfortunately I can't provide the HDF files I'm using, and if you want
to see the smb.conf let me know and I can try to get that posted.

If anyone has any insight or help to offer, it would be appreciated.

Thanks.

Kevin Taylor
 		 	   		  
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Just to add a little info, we found that Windows XP has some sort of internal
read buffer of around 67,076,095 bytes. There's a couple of references to a
number like that on the internet.

However, a windows 2008 server share seems to ignore, or account for that buffer
and handles the reads properly, but a Samba share does not.

Does anyone have any thoughts or ideas on a setting that might help?


> From: groucho.64738 at hotmail.com
> To: samba at lists.samba.org
> Date: Wed, 7 Apr 2010 09:41:41 -0400
> Subject: [Samba] samba server file read size limit of 64MB for HDF files
> 
> 
> Sorry if that's a vague subject, but this problem is a little weird and
I'm just wondering if there are any suggestions out there.
> 
> We've got a Samba server (3.0.23) running on a CentOS 5.3 server
offering up a data share of 7TB on an XFS filesystem. The authentication all
happens through a Samba PDC with an LDAP backend all on a different server. The
system in question is just a domain member fileserver.
> 
> On the data share are several HDF files that we try to read into a couple
of different applications on XP. I'm using the Compaq Array Visualizer just
to look at them. The files on the server are owned by root, and world
read/writable. As a regular user on the XP client, if I look at one of the files
that's ~30MB in size, I'm presented with all the numbers I expect to
see. If I look at a file that's larger than 64MB (80MB for the specific ones
I was testing, but we've found the problem after 64MB in size) I no longer
see the numbers that I would expect...it's all zeroed out at the beginning.
> 
> If I copy the 80MB HDF to my local XP workstation, it works fine, so
it's not a corrupted file or anything.
> 
> The weird part is that if I go onto the linux server and change the
ownership of the file to my regular user account, it all works fine...I can read
the 80MB file through samba and see all the numbers I should...but no other
users can. If I change the ownership to someone else, they can then see it all,
and I can't again.
> 
> At one point all of these files were hosted from a Windows 2008 Server, and
never experienced these problems, only after the move to the Samba server.
> 
> The fact that anything smaller than 64MB works, starts to sound like a
possible setting that I can change.
> 
> Unfortunately I can't provide the HDF files I'm using, and if you
want to see the smb.conf let me know and I can try to get that posted.
> 
> If anyone has any insight or help to offer, it would be appreciated.
> 
> Thanks.
> 
> Kevin Taylor
>  		 	   		  
> _________________________________________________________________
> Hotmail is redefining busy with tools for the New Busy. Get more from your
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>
http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_2
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> To unsubscribe from this list go to the following URL and read the
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