Users Guide

• Provides uptime for all storage applications even when a controller stops functioning.
• Provides access to critical functions of the chassis at all times.
• Enables server to handle situations when controller stops functioning are becomes faulty.
• Makes use of component redundancy
Using the fault-tolerant feature of controllers, you can manage the tasks associated with shared storage that are achieved by having an
active and passive (peer) controller. Active controller is the controller that is active and monitors all the storage-related processes. Working
status of both controllers are communicated between controllers so that when an active controller stops functioning, the passive controller
acting as a peer hot-spare, takes over in a seamless manner.
NOTE: CMC displays fault-tolerant data for Shared PERC 8’s with SR-IOV enabled rmware. If a non-SR-IOV card is attached to
the shared storage slots the card does not power on and an alert is generated.
NOTE: Operations such as resetting CMC, which reset the CMC conguration, reset the external fault-tolerant conguration. As
a result, the PERC mode changes to "Safe mode". Disable the fault-tolerance in the external PERC.
Security Key Mismatch
You can create a security key on a controller using an Encryption keyID and a Passphrase. The controller compares only the Passphrase
used while creating security key to identify whether the two controllers have the same security keys. Therefore, two controllers joining a
cluster are fault-tolerant even if they have dierent Encryption Key ID as long as they have the same passphrase.
If a security key mismatch is detected between two peer controllers, the fault-tolerant mode changes to ‘Degraded’. A critical alert is
displayed on the Chassis Health page and monitoring may not display proper drive association.
If a security key mismatch is detected, resolve the key mismatch by creating, modifying, or deleting the security key on one of the
controllers, before performing any other storage security operation on the controller. Power cycle the chassis after resolving the mismatch.
Before combining two non-high availability controllers, modify the keys so that they match. This action facilitates import of secure drives
associated with each controller joining the cluster.
For external controllers, modify the keys so that they match before cabling them for fault tolerance. The modication of security keys
facilitates import of secure drives associated with each controller joining the cluster.
Resolving Security Key Mismatch Using CMC Web Interface
To resolve the security key mismatch using the CMC web interface:
1 Turn o the server modules.
2 Click Server Overview > Power > Control > Power O Server.
3 Modify the security key on one or both of the existing non-fault-tolerant controllers so that the keys match.
4 Power cycle the chassis.
5 Verify if the controllers have matching keys.
Viewing Controller Properties Using CMC Web
Interface
To view the controller properties:
1 In the left pane, click Chassis Overview > Controller.
2 On the Controllers page, under the Controllers section, you can see the basic properties of the controller. However, to view the
advanced properties, click the .
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Managing Chassis Storage