HP 3PAR Geocluster Software - Manual (Page 27)

3PAR GeoCluster 1.0.0.14 for Windows User’s Guide
320-200263 Page 27
4.1 Recovering from a Failover.
4.1.1 3PAR GeoCluster for Windows resource Decision Matrix
During the failover process, every time MSCS calls upon a Services and applications group
on a node, it will first trigger the 3PAR GeoCluster for Windows resource, provided this
resource is at the top of the dependencies hierarchy. See section 3.4 Dependencies for
more information. The resource will then go through one of the following decision
matrices, in order to determine its status. Most decision outcomes will cause no noticeable
consequences, as they correspond to the expectable behavior of MSCS (simply put, if a
3PAR GeoCluster for Windows resource is not supposed to come online, it will expectably
not come online). Only two behaviors, described below, require administrator attention:
Online after reverse and Online after failover.
4.1.1.1 Remote Copy is fully functional.
The 3PAR GeoCluster for Windows resource will consider that Remote Copy is fully
functional if the following conditions are met:

Remote Copy System is started.

The Remote Copy group is started.
It will then consider the role of the Remote Copy group it is linked to on its local InServ
storage array and the role of the corresponding Remote Copy group located on the remote
site InServ storage array and decide whether to come online successfully, as follows:
Local Remote Copy
Group Role Remote Copy Group Role Outcome
Primary Secondary Online
Primary Other than Secondary Failed
Primary-Rev Secondary-Rev Online
Secondary Primary Online after reverse*
Secondary-Rev Any Failed
NOTE: “Online after reverse” means that MSCS is bringing the 3PAR
GeoCluster for Windows resource online on a cluster node located on the
remote site. As long as the replication is functional, this switch in roles
will cause the Remote Copy setup to reverse the replication process. The
secondary Remote Copy group will have its role changed to primary and
the primary Remote Copy group will become secondary. This is a specific
failover scenario, which is addressed later in this chapter.