Unable to mount a DFS share with CIFS [solved]

Zwartoog · Last edited by Zwartoog on Thu Jan 28, 2010 9:19 am; edited 1 time in total

Dear users,

I am trying to mount a DFS (Distributed File System) share with CIFS. The server has Windows Server 2003 installed.

On my Gentoo box, I am currently running kernel 2.6.30-gentoo-r5 and samba-libs/samba-client-3.4.3:

drescherjm · Posted: Mon Jan 25, 2010 9:31 pm Post subject:

Did you get anywhere with this?

If I mount as root I do not get the operation not supported it just does not traverse the dfs links.

I get errors like

drescherjm · Posted: Mon Jan 25, 2010 11:28 pm Post subject:

Fixed. I needed to upgrade my kernel from 2.6.27-ovz. I installed gentoo-sources-2.6.32-r2 and all was well.

Zwartoog · Posted: Wed Jan 27, 2010 1:30 pm Post subject:

Hi drescherjm! Glad to hear everything is working now!

Unfortunately, it still does not for me. Today I have upgraded to 2.6.32-r2 and samba 3.5.0-rc2. Mounting the DFS goes without errors, but the (DFS) shared directories on the server are still empty (no error messages are given).

I have tried to use the samba4 use-flag without success. Searching the internet again learned me that the problem is frequently occuring, but all were solved by installing keyutils and updating /etc/request-key.conf with:

create cifs.spnego * * /usr/sbin/cifs.upcall %k
create dns_resolver * * /usr/sbin/cifs.upcall %k

Unfortunately, not for me...

If anyone has an idea on how to research this problem, I am happy to hear about it.
_________________
The box said "Requires Windows 95 or better", so I installed Linux.

drescherjm · Posted: Wed Jan 27, 2010 1:38 pm Post subject:

I am using samba-3.0.37 on most of the dfs mounts including the dfs root. I am not sure if I tried connecting to the one server in the dfs that is samba 3.4.5. The samba dfs root is also 2.6.32 but that is vserver-sources. With the client being gentoo sources. The client is the machine that has samba-3.4.5. I did not mess with any /etc files. My network has samba pdcs and openldap. With no windows servers but windows and linux cifs clients.

I know this sounds complicated. Hopefully this can help you..

There was one change I had to make since I have been forced to not having a dns server (company network security police :evil:

) was I had to replace the UNC names with ipaddresses in the dns root.

Zwartoog · Posted: Wed Jan 27, 2010 2:10 pm Post subject:

My server runs Windows Server 2003 R2 3790 Service Pack 2 without any special settings (as far as my local sysop knows).

Curious: how do you make symlinks to msdfs:// ?
_________________
The box said "Requires Windows 95 or better", so I installed Linux.

drescherjm · Posted: Wed Jan 27, 2010 2:19 pm Post subject:

My dfs root is on a gentoo samba server. That last output with the msdfs:// links were from the dfs root. You may be able to create a second root on a linux machine to mirror the root on your windows server.

Here is the samba definition for the samba dfs root.

Zwartoog · Posted: Wed Jan 27, 2010 2:24 pm Post subject:

Ok, I may be missing something trivial here. How are the msdfs links followed? E.g. my shell does not recognize the msdfs protocol. Or are those links only valid on servers and interpreted by samba-server?
_________________
The box said "Requires Windows 95 or better", so I installed Linux.

drescherjm · Posted: Wed Jan 27, 2010 2:43 pm Post subject:

In the linux client that has the samba dfs root cifs mounted (and also has the proper kernel) the msdfs:// links automatically get translated. Without the proper client kernel I used to see msdfs:// and not be able to traverse the paths in the shell.
_________________
John

My gentoo overlay
Instructons for overlay

Zwartoog · Posted: Wed Jan 27, 2010 2:46 pm Post subject:

Which kernel options did you set? I thought:

drescherjm · Posted: Wed Jan 27, 2010 2:47 pm Post subject:

Zwartoog · Posted: Wed Jan 27, 2010 2:57 pm Post subject:

Got it, but now I am puzzled again

On amd64, there is no such configuration option. DFS is supposed to be in the EXPERIMENTAL part. However, x86 seems to have this DFS option explicit.

I will try to get it to work on the x86 box again (although it is in production, so my options are limited). For now, let's see what happens if I manually add the kernel option to the config on the amd64 box.

Btw, you ARE running x86, right? Otherwise I do not know why this option only appears on the x86 box.
_________________
The box said "Requires Windows 95 or better", so I installed Linux.

drescherjm · Posted: Wed Jan 27, 2010 2:59 pm Post subject:

amd64 on all linux machines

Here is the client:

Zwartoog · Posted: Wed Jan 27, 2010 3:25 pm Post subject:

Got it! It needs CONFIG_KEYS=y in the security section to be set as well.

And guess what: it works!

Well, almost: I seem to have some troubles with resolving hostnames:

ls: cannot access /mnt/dfs/dfsmount: Resource temporarily unavailable

And from /var/log/messages:
CIFS VFS: dns_resolve_server_name_to_ip: unable to resolve: dfshost2
CIFS VFS: cifs_compose_mount_options: Failed to resolve server part of \\dfshost2\users$ to IP: -11

but I think I know where that problem originates (we have different domain settings in the network due to migrations). Seems the original problem is fixed, I will make a final post later to summarize everything.

Thans a lot drescherjm!
_________________
The box said "Requires Windows 95 or better", so I installed Linux.

drescherjm · Posted: Wed Jan 27, 2010 3:35 pm Post subject:

Zwartoog · Posted: Thu Jan 28, 2010 9:18 am Post subject:

Ok, so how to get DFS working these days?

First, you need a fairly recent kernel. 2.6.32-r2 seems to work. Configure it with: