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

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How Connections Are Established

To better understand how Storage Mirroring connections work, the following diagram identifies the sequential steps

completed when establishing a Storage Mirroring connection. Each numbered step is described below the diagram.

1. When the client initiates a connection, the Storage Mirroring source machine validates the data contained in the

replication set and the target information entered in the Connection Manager. The source machine verifies that if the

same source and target are connected through a different replication set, the specified target path is not already in use. If

the target path is in use by another Storage Mirroring connection, the potential for data overwrites exists. Therefore, if

one-to-one configuration is being used, Storage Mirroring will not allow a connection to the same path.

2. After the connection information is validated, the replication set database is sent to the target machine as a backup. The

file on the target machine is identical to the source’s machine name so that the file can be recovered if the source

machine crashes.

3. The source establishes transmission queues. Mirror and replication data is put onto these queues. For example, when

using a slow network or target machine, the data is updated on the source faster than it can be transmitted to the target.

The data is stored on a queue so that it is not lost.

4. A logical Storage Mirroring connection is established. This is the connection that is visible through the Storage Mirroring

client applications.

5. If mirroring or replication begins on connection, a network connection is established and the transmission of data begins

immediately. If no activity is set to occur on connection, the network link is established when mirroring and replication

are triggered.

Source

Target

Replication Set

Transmission

Queues

Replication Set

Backup