When working with NDS/eDirectory Replicas (NetWare 6.x) you need to have one that is the Master Replica. This is a flag but it's an important flag because it ensures at least one replica has the control, that if the synchronisation process is in doubt, it will use the objects/properties from the Master Replica.
Sometimes when you are upgrading or migrating to new hardware you may need to change the Master Replica to one on another server. Usually you can do this easily with DSREPAIR | Advanced options menu | Replica and partition operations | Designate this server as the new master replica server.
I have found that sometimes this is not enough. After using DSREPAIR (as above) it appears as if the server's replica is the Master. But look on the other server, the one that used to be the Master. It is possible that it has not changed to Read/Write. In fact the designation of the new server to Master has not happened! It just didn't work. If you don't notice this you can get yourself into some more problems later - I am speaking from experience!
Instead of using DSREPAIR to change the Master flag, use ConsoleOne. You can run ConsoleOne on the server console - here's what to do:
Go to the server
Press Ctrl-Esc, 1-System Console
Click ConsoleOne (on the Novell menu)
Click View | Partition and Replica View
Click on the server object you want to set as Master
Right click and click Master
Wait... also you may need to close ConsoleOne and reopen it before it reappears correctly on the screen set to Master.
This is by no means the solution to all such situations. Of course you need to ensure your replicas are sychronised properly and use DSREPAIR to ensure there are no errors before you start. The best advice is to always check that an operation such as changing the Master designation, has actually worked. Even if it appears to have worked, look at it from a different angle or using a different tool (such as ConsoleOne or DSREPAIR on another server). Be sure you understand what is happening before you continue. Take your time and you should be fine - although that is good advice for everything to do with computers! ;-)