Users Guide

• Run the RACADM cmcchangeover command. (See the cmcchangeover command section in the

Chassis Management Controller for Dell PowerEdge M1000e RACADM Command Line Reference

Guide).

• Run the RACADM racreset command on the active CMC. (See the racreset command section in the

Chassis Management Controller for Dell PowerEdge M1000e RACADM Command Line Reference

Guide).

• Reset the active CMC from Web interface. (See the Reset CMC option for Power Control Operations

that is described in Executing Power Control Operations.)

• Remove the network cable from the active CMC.

• Remove the active CMC from the chassis.

• Initiate a CMC firmware flash on the active CMC.

• Have an active CMC that is no longer functional.

NOTE: In the event of a CMC failover, all iDRAC connections and all active CMC sessions are

lost. Users with lost sessions must reconnect to the new active CMC.

Related Concepts

About Standby CMC

CMC Failsafe Mode

Active CMC Election Process

Obtaining Health Status of Redundant CMC

About Standby CMC

The standby CMC is identical to and is maintained as a mirror of the active CMC. The active and standby

CMCs must both be installed with the same firmware revision. If the firmware revisions differ, the system

reports as redundancy degraded.

The standby CMC assumes the same settings and properties of the active CMC. You must maintain the

same firmware version on both CMCs, but you do not need to duplicate configuration settings on the

standby CMC.

NOTE: For information about installing a standby CMC, see the Hardware Owner’s Manual. For

instructions on installing CMC firmware on your standby CMC, follow the instructions in Updating

Firmware.

CMC Failsafe Mode

The M1000e enclosure enables the fail-safe mode to protect the blades and I/O modules from failures.

The fail-safe mode is enabled when no CMC is in control of the chassis. During the CMC failover period

or during a single CMC management loss:

• You cannot turn on newly installed blades.

• You cannot access existing blades remotely.

• Chassis cooling fans run at 100% for thermal protection of the components.

• Blade performance reduces to limit power consumption until management of the CMC is restored.

The following are some of the conditions that can result in CMC management loss:

• CMC removal — Chassis management resumes after replacing CMC, or after failover to standby CMC.

• CMC network cable removal or network connection loss — Chassis management resumes after the

chassis fails over to the standby CMC. Network failover is only enabled in redundant CMC mode.