The main advantage of clusters is protection against hardware failure. Should the primary node fail or otherwise become unavailable, applications can continue to run by transferring their execution to standby nodes in the cluster.
CVM can be deployed in the control domains of multiple physical hosts running Oracle VM Server for SPARC, providing high availability of the control domain.
Figure: CVM configuration in an Oracle VM Server for SPARC environment illustrates a CVM configuration.
If a control domain encounters a hardware or software failure causing the domain to shut down, all applications running in the guest domains on that host are also affected. These applications can be failed over and restarted inside guests running on another active node of the cluster.
Shared volumes and their snapshots can be used as a backing store for guest domains.
The following example procedure shows how snapshots of shared volumes are administered in such an environment. In the example, datavol1 is a shared volume being used by guest domain ldom1 and c0d1s2 is the front end for this volume visible from ldom1.
To take a snapshot of datavol1
primary# ldm stop ldom1
primary# ldm unbind ldom1
This ensures that all the file system metadata is flushed down to the backend volume, datavol1.
See the Veritas Storage Foundation Administrator's Guide for information on creating and managing third-mirror break-off snapshots.
primary# ldm bind ldom1
primary# ldm start ldom1