If a Backend Server in a Static Cluster is shut down, all Accounts hosted on that Server become unavailable (there is no interrupt in service for Accounts hosted on other Backend Servers).
To restore access to the Accounts hosted on the failed Server, its Account Storage should be connected to any other Backend server. You can either:
After a sibling Backend server gets physical access to Account Storage of the failed server, you should modify the Directory so all Servers will contact the new "home" for Accounts in that Storage. This can be done by an LDAP utility that modifies all records in the Domains Subtree that contain the name of the failed Server as the hostServer attribute value. The utility should set the attribute value to the name of the new Host Server, and should add the oldHostServer attribute with the name of the original Host Server. This additional attribute will allow you to restore the hostServer attribute value after the original Host Server is restored and the Account Storage is reconnected to it. If the CommuniGate Pro is used as the site Directory Server, 500,000 Directory records can be modified within 1-2 minutes.