Administrator Guide

Table Of Contents
Figure 6. Synchronous consistency group
The hosts at both clusters write to the metro node distributed volumes in the consistency group.
Metro node writes data to the back-end storage on both clusters
An acknowledgment is returned to the host that is issuing the write.
This guarantees that the image on the back end storage is an exact copy on both sides.
Synchronous consistency groups: visibility
Synchronous consistency groups support either distributed or local volumes (but not both in the same consistency group).
Local synchronous consistency groups have only local volumes as members. Local synchronous consistency groups can have the
Visibility property set to either:
Local visibility- The local volumes in the consistency group are visible only to local cluster.
Global visibility- The local volumes in the consistency group have storage at one cluster, but are visible to both clusters.
Local visibility
Local consistency groups with the Visibility property set only to the local cluster read and write only to their local cluster.
The following figure shows a local consistency group with local visibility.
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Consistency Groups