eDirectory offers the NetIQ robust directory service and the fault tolerance inherent in replication. Replication allows you to keep copies of the eDirectory database, or portions of it, on multiple servers at once.
You cannot configure encrypted replication through iManager if any server in the replica ring is down.
When encrypted replication is enabled, merging trees fails. Disable secure replication on each tree before doing a merge. If the trees have EBA enabled servers, then tree-merge may succeed. However, post-merge, the tree becomes unstable and the replication is improper causing authentications to fail
You should always keep multiple replicas of eDirectory partitions. If you do so and one replica becomes corrupted or is lost because of a failed hard disk, you can delete that replica using NetIQ iManager and replace it with a new one from the intact replica.
For more information on deleting replicas, see Administering Replicas in the NetIQ eDirectory 9.0 Administration Guide.