10.7.2: still can't replicate 10.6 Open Directory or restore from backup

Question

I am trying to migrate my Open Directory (OD) database from an Xserve running 10.6.8 to an iMac running 10.7.2 now. As before the update to 10.7.2, I am unable to make the Lion server an OD replica of the OD database running on Snow Leopard.
This is what I do (please let me know, if anyting I do is wrong):
On the Snow Leopard Server (SLS) in the Server Admin utility, I go to the Open Directory service, the "Archive" subsection, choose a target directory for "Archive In", and click on the Archive button. I am then asked to name my archived database and provide a password. Let's say, it is "OD Archive," the file generated will be "OD Archive.sparseimage".
I copy this Sparseimage to the deskop of my Leopard Server (LS).
I then open the same place in the Server Admin utility on the LS. In the "Restore from" section I browse to the LS desktop and "Choose" the saved Sparseimage. I click on "Restore," at which point I am asked for the password of the archived OD database. When I supply it, it appears that my OD archive is being imported.
However, going into the Workgroup Manager on the LS, and logging in as diradmin, into /LDAPv3/127.0.0.1, shows no users from my SLS having been migrated. Why has this still not been fixed?
Likewise, when I try to make the LS an Open Directory replica of the SLS, I again, even after this updated informed that my OD database admin credentials are incorrect, when they are not. I had surely expeced a fix for this by the time we reached 10.7.2.

Answer 1

Historically you have not been able to mix versions between an Open Directory Master and Replica, that is both would either have to be Snow Leopard, or both would have to be Lion.
I have not tried upgrading to Lion this way (I am currently leaving my servers on Snow Leopard) but I can suggest the following based on experiences with Snow Leopard Servers.
As you already appear to have done, in Snow Leopard Server make an Archive of your Open Directory setup
Make sure you also have a backup of the entire Snow Leopard Server so you can go back to it if you can't successfully move to Lion
Setup the hostname, IP address and DNS records (which might mean setting up a DNS server) for the new Lion Server
Check this using the command line
sudo changeip -checkhostname
Make the new Lion Server in to a new empty Open Directory Master
Test this new Open Directory Master by creating a test user and then deleting afterwards
Now move on to the restoring of the Open Directory Archive, when I did this last time, I found that I was given two choices, either to completely replace the Open Directory with the one from the Archive, or to merge the two together. I found that trying to replace failed and resulted in an empty Open Directory like you report, I found that chosing merge did work successfully
If the above still does not work, then you might have to consider the following alternative approach.
On the Snow Leopard Server in Workgroup Manager export all the user accounts except the Admin and DirAdmin accounts
Optionally export all the Groups
Optionally export all the Computer Groups
Setup the new Lion Server
Create a new empty Open Directory
Import the files exported from Workgroup Manager
This will not keep the original passwords. You will have to set a password for each account.