I’ve found that there are a couple of things to do with the configuration.
I’m running 1.5.4 version and I’m experiencing the same issue.

To put this in context, I’ve installed the fog server and then the IP of this machine needed to be changed, originally it had 192.168.27.40 and now it’s 10.0.0.1

With this in mind, I found the same error than you.

As @Tom-Elliott stated I haven’t created the /home/fog/images neither /home/fog/images/dev, using his advice I created them and also created the .mntcheck files.

Then I modified the /etc/exports to reflect the changes, updating the paths to the new ones.

After that, as @Kiweegie wrote I executed exportfs -a, please notice that in the second line he proposes to modify the line of the /etc/exportfs adding an async modifier that nowadays is in place out of the box.

After all that changes, my client started but gave me a NFS timeout, looking at the error message I’ve noticed that the IP of the NFS export and the path weren’t correct yet.

Looking at file /var/www/html/fog/lib/fog/config.class.php I found that there are two values that should be updated
STORAGE_DATADIR
STORAGE_DATADIR_CAPTURE

I added the right path in both.

Tried to reboot the client but I received the same timeout.

So I ended up checking the configuration of my storage nodes at the UI.

I found that, in the storage node definition form there were a couple of fields where still had the wrong values:

• IP Address
• Image Path
• FTP Path

I updated them and now it seems to be working properly, at least the image capture step.

I hope this can help anyone.