Storage Mirroring Evaluation Guide

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1.2.3 Failure monitoring/failover
Failover is a process in which a target machine stands in for a failed source machine. As a result,
user and application requests that are directed to the failed source machine are routed to the
target machine.
HP OpenView Storage Mirroring monitors the status of machines by tracking network requests
and responses exchanged between source and target machines. When a monitored machine
misses a user-defined number of requests, HP OpenView Storage Mirroring assumes that the
machine has failed. HP OpenView Storage Mirroring then prompts the network administrator to
initiate failover, or, if configured, it occurs automatically.
The failover target assumes the network identity of the failed source. When the target assumes
the identity of the source, user and application requests destined for the source machine or its
IP address(es) are routed to the target. After failover, user and application requests directed to
the source machine are routed to the target machine.
When partnered with HP OpenView Storage Mirroring’s data replication capabilities, failover
routes user and application requests with minimal disruption and little or no data loss. In some
cases, failover may be used without data replication to ensure high availability on a machine that
only provides processing services, such as a web server.
Source Name: Marketing
User and application requests sent to
the source by locating the IP address
Before
IP Address: 125.7.82.43
Target Name: Backup
IP Address: 125.7.82.67
Failover
Occurs
Failed Source
User and application requests sent to
the source by locating the IP address
After
Target Name: Backup
and Marketing
Failover
Occurs
IP Address: 125.7.82.67
and 125.7.82.43