HP StorageWorks Storage Mirroring for Linux Evaluation Guide (T2558-96079, February 2008)

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Initiating a failure
If you want to continue with the remaining portions of this evaluation, failback and restore, then you will need to initiate a
failure of your source machine.
1. Ping the source’s IP address from your client machine.
2. The Failover Control Center does not have to be running in order for failover to occur. For the purpose of this
evaluation, make sure that it is running so that you can see each step of the process.
3. Disconnect the network cable on the source. Notice immediately, that the Failover Control Center Time to Fail counter
decreases and never resets. You will see the icons change to yellow and eventually to red. Once the icons are red and
the Failed Over message is displayed, failover has occurred.
4. Ping the source’s IP address from your client machine.
As you can see, the target has taken on the identify of the source. Application and user requests destined for the source are
routed directly to the target. The impact on your end users is minimal.
Performing failback
While your source is failed over to your target, end users continue to work without interruption and the data on the target
is being updated. If this was a real-world scenario, you would have the opportunity to fix the problems on the source, without
downtime for your end users because the target is standing in for the failed server. When you have resolved the problems on
the source, you are ready to perform failback. Failback reverts the target back to its original identity so that the source can
be brought online. After failback, your data on the source is out-of-date. You will want to restore the newer data from the
target so that the two machines will again be synchronized.
To test the restoration, you need to simulate the changes that the end users would have made on the target while the source
was unavailable.
1. Like you did earlier, edit the same file, but this time on the target. Save your changes.
2. Modify the other three files so that the date, time, and/or size is updated.
3. Before bringing your source machine back online, you will need to disconnect your existing connection. This step is in
preparation for the restoration that will be performed in the next section. Open the Storage Mirroring Management
Console on the source, login to the source server, right-click the connection, and select Disconnect.
4. Now, from the Failover Control Center on your client machine, select the target machine that is standing in for the
failed source.