The master replica is a writable replica type used to initiate changes to an object or NDS Partition. The NDS Master Replica manages the following types of NDS Partition operations:
The NDS Master Replica is also used to perform the following types of eDirectory object operations:
By default, the first eDirectory server on your network becomes NDS Master Replica. There is only one NDS Master Replica for each partition at a time. If other replicas are created, they are read/write replicas by default.
If you're going to bring down the server holding a NDS Master Replica for longer than a day or two, you can make one of the read/write replicas the master. The original master replica automatically becomes read/write.
A master replica MUST be available on the network for eDirectory to perform operations such as creating a new replica or creating a new NDS Partition.
Do NOT confuse eDirectory NDS Master Replica with LDAP Multi-master replication. All Edirectory and Read/Write Replica servers are LDAP Multi-master Servers.