Users Guide

Figure 2. Network and power outage—flowchart
The alert, CDEV4007, is related to network or power issues that can be classified as:
● Intermittent/recoverable issues—Momentary power or network outages. The administrator can identify these types of
failures and perform recovery actions locally or remotely. Do not promote the backup lead. Allow the lead chassis to recover
connectivity automatically or the administrator fixes the power or network issues.
● Partial failure—Both management modules fail or malfunction. But the remaining chassis components are working.
Promote the backup lead as the lead chassis to regain group management function through the new lead. For more
information about promoting the backup and restoring the failed lead chassis to production state, see the section, Disaster
recovery of lead chassis.
● Complete failure—Catastrophic failures. All the chassis components including the management modules are broken or
nonresponsive. Promote the backup lead as the lead chassis to regain group management function through the new lead. For
information about promoting the backup lead and clearing references to the failed lead chassis, see the section, Disaster
recovery of lead chassis.
Scenarios when backup lead can take over as lead
chassis
This section describes the situations in which a backup lead can take over as the lead chassis of the chassis group.
Disaster recovery of lead chassis
Catastrophic failures such as power loss, network loss, and failure of both MMs can result in the lead chassis being inaccessible
or unavailable. In such cases, you can promote the backup to take over from the failed lead chassis for continued management
of systems.
NOTE:
Promoting the backup lead as the new lead restores the group management function for the member chassis that
are not exposed to the failures. However, there are limitations on the extent of the functionality can be restored on the
failed lead chassis. The restoration is based on the severity of the failures in the failed lead chassis.
Remember the following while recovering the lead chassis:
108
Use case scenarios