[Samba] Problem After Upgrade - NT_STATUS_FILE_IS_A_DIRECTORY

[Robert Heller]

At Wed, 07 Jul 2010 13:19:43 -0400 ltracchia at alexanderconsultants.net wrote:

> 
> > This is truly a bad idea. That XP share should be
> > mounted by the workstations just like the server
> > shares. Move the data to the server, or use the XP box
> > as a server to directly serve those who need the data
> > on it.
> >
> > Cheers,
> >
> > TMS III
> >
> 
> Why is this a bad idea? We've been running this setup 
> for a few years now and its been working fine until we 
> upgraded. The XP box only allows 10 user limit for 
> shares, so that's why we mounted it to the Ubuntu 
> server and shared it with Samba instead of having to 
> pay for Windows Server license.
> 
> The problem with simply moving the files over to the 
> Ubuntu server is that the files on the XP box are 
> stored on a RAID array that comes with a controller 
> card whose driver is really only designed to be run on 
> Windows, not Linux.

Is this a *real* RAID controller or a 'fake' (BIOS/Software/MB) RAID
controller?  If it is a real controller are you sure there is no Linux
driver for it?  (Esp. since you are using Ubuntu!) If it is a
software/BIOS/MB RAID controller the performance is going to be really
bad -- these controllers are really only meant for home systems and not
really for true servers.

> 
> I'd have to setup mdadm on Ubuntu, which I've done 
> before and was not impressed. The Windows RAID system 
> we have is much more easier to maintain.

Oh, you mean you have to actually use your keyboard? How dreadfull...

Do you mean to say that the files local to the Ubuntu *server* are not on
a RAID array? 

> 
> I don't want to get off topic here, I just want to 
> know why Samba is giving me trouble browsing these 
> mounted directories.

This sort of 'game' (mounting files from one 'server' on another server
and then re-exporting them), is not *specific* to Samba.  See what
happens when you try to NFS export file systems mounted as nfs file
systems (although I expect nfsd/mountd would refuse to let you do that
in the first place).

There are several problems:

It tends to confuse the server(s).  File serving software (Samba, NFSD,
etc.) really expect the data they are serving to be local (yes, using a
NAS or something like that is a little different) and are written to
optimal to work that way.

It causes lots of network traffic: every I/O operation causes two
batches of network traffic and implies two sets of network channels: one
set between the machine with the physical disks (the XP box) and the
'server' (the Ubuntu box), and a *second* set of network channels
between the 'server' (the Ubuntu box) and the final client(s) (the
client MS-Windows machine(s)).  If this is on one physical network (if
the 'server' (the Ubuntu box) only has one NIC), then the you have lots
of network collisions, which means your network thoughput will truely
suck (eg network timeouts, dropped/lost packets, etc.). 

I expect that 'before' you 'got by' by luck.  What might be happening
now is that some fix to Samba is biting you or maybe you are getting
network I/O errors (timeouts?) because of what I described in the
paragraph above.

What you are doing is not really going to work in the long term.  You
either need to:

1) Buy a real, supported RAID card for the Ubuntu system.
2) Live with mdadm
3) Pay for licenses for the XP system.


-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Download the Model Railroad System
http://www.deepsoft.com/  -- Binaries for Linux and MS-Windows
heller at deepsoft.com       -- http://www.deepsoft.com/ModelRailroadSystem/