nfs mount in CentOS 6 changed from CentOS 5?

[Slater]

Hi Experts,

I have two servers, one running CentOS 5.4 (Lets call it A) and another running CentOS 6.5 (Lets call it B).

Server A has been using a SnapServer (and NAS device that provides SMB and NFS services) for backups for years without any problem, to mount I use the following command:

mount 192.168.4.2:/myshare /mnt/snap/ -t nfs -o rw

Now, if I try to use the same command from the new server B, configured, I believe, in the same way as server A, I get a timeout, i.e. either the Snap is not responding or something in the way stops the communication.

I both cases I am using the same user and the user is enabled in the SnapServer NFS configuration to access from both ip's (of servers A & B).
All three machines are in the same network. My first suspicion was the firewall in server B, but disabling the firewall in B does not solve the problem, and there is no firewall in the Snap.
I can ping the Snap from both servers and can also access the share from many other machines running Windows. Just the server B is refusing to mount.

On the other hand, I can see AND mount some of the Snap shares from server B wia the GUI going to Places > Connect to Server and specifying "windows share" (there is no option for NFS) and clicking on Connect. Accessing this way though is not exactly the same as doing it from Windows machines, since the same user has permisions when connecting from Windows that are missing when connecting from server B. Likewise, I can also see the Snap going to Places > Network > Windows Network > myworkgroup.

Any ideas to help identify the problem?

[jscarville]

AFAIK, NFS v3 and v4 work the same on 5 and 6. Check for IP restrictions on the NAS.

[Slater]

This was my first suspicion, but I do not see what could be wrong, since it is a very simple configuration in the Snap, with only two entries. The first one corresponds to the server B (not able to mount) and the second to the server A (which works as expected). UID = 0 is obviously root in both machines, and both have the same password.

UID: 0
IP Address: 192.168.4.10
Address Mask: 255.255.255.255

--------------------------------------------------------------------------------
UID: 0
IP Address: 192.168.4.9
Address Mask: 255.255.255.255

On the other hand, reviewing the SnapOS Specifications (this is the OS running on the Snap, I believe it is based on Linux), i find the following: (i have deleted a few irrelevant lines):

Network File Protocols
--------------------------
Microsoft Networks (CIFS/SMB), UNIX (NFS v2/3), Apple (AFP 2.0), Internet (HTTP 1.1), File Transport Protocol (FTP)

Network Client Types
-------------------------
Windows: 95, 98,Me, NT 4.0, 2000, 2003, XP
Macintosh: OS 8.x, 9.x, 10.x
UNIX: Solaris 7, 8, 9; HP-UX 11; AIX 4.3.3, 5.x
Linux: Red Hat Linux 7.x, 8.x, 9.x

Since CentOS 6.5 is giving me troubles in both CIFS and NFS (CIFS because eventhough is mounting, is not behaving like the rest of Windows machines, as I said before, and NFS because is not even mounting), I suspect that the problem in on the CentOS 6.5 side. In particular my concern is whether CentOS 6.5 can work with a machine that supports only NFS V2/3 or if it has to be tunned somehow.

RHEL is not even mentioned (obviously because it did not exist at this time). But since it works fine with CentOS/RHEL 5, should I expect it to work ask well in CentOS 6?

[gerald_clark]

You may try adding "-o nfsvers=3" to your mount command.

from "man nfs"

[Slater]

That was it!

The rw option is not even necessary, it seems to get "rw" by default. So the command is:

mount 192.168.4.2:/myshare /mnt/snap/ -t nfs -o nfsvers=3

Problem solved and thanks a lot.

[milne30]

Thank you - this helped me out alot i have been racking my brain for the last 12 hours trying to know why this was not mounting.