HP OpenView Storage Mirroring User Guide (360226-002, May 2004)

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Windows NT 4.0
! Storage Mirroring failover can monitor an unlimited number of source machines (limited only by the number of IP address
placeholders that exist) and can assume the identity of multiple sources.
! During the failover process, by default, the target can maintain its original identity and add the name(s) and IP address(es)
of one or more failed source machines.
! The target can optionally be configured to replace its original identity with that of the source machine. When replace is
selected, the target can only assume the identity of one source at a time. It is, however, possible to fail over for other
sources by adding their identity. Replacing is available for applications that rely on the primary machine name and are
sensitive to machine name changes. It is possible to replace the target identity with one source and then add the identity
of other source machines.
! If the identity of the source is added to the target during failover, no services are stopped or restarted. If the identity of
the target is replaced by the source, the Computer Browser, Net Logon, and Server services are stopped and restarted
during both failover and failback. Other services may be stopped or restarted as needed using failover and failback scripts.
! If the identity of the source replaces the target during failover, the target machine must be a PDC/BDC or the target will
lose authentication with the domain.
! The following table describes the source and target configurations of Windows NT 4.0 machines that are supported by
Storage Mirroring.
Ta r g e t
Primary Domain
Controller
Backup Domain
Controller
Member
Source
Primary Domain Controller
X
a
a. After failover, the target will have the functionality of a BDC, not a PDC, but could be promoted to a PDC.
X
b
b. After failover, the target will have the functionality of a member, not a PDC. It is necessary to promote a BDC
so that users/groups can be added, deleted, or modified. The user will not be able to log into the domain unless there
is a BDC.
Backup Domain Controller
XX
X
c
c. After failover, the target will have the functionality of a member, not a BDC.
Member XXX