About standby cmc, Cmc failsafe mode, Active cmc election process – Dell POWEREDGE M1000E User Manual
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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
.
CMC Failsafe Mode
In the failsafe mode, similar to the failover protection offered by the redundant CMC, 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.
•
CMC reset — Chassis management resumes after CMC reboots or chassis fails over to the standby CMC.
•
CMC failover command issued — Chassis management resumes after the chassis fails over to the standby CMC.
•
CMC firmware update — Chassis management resumes after CMC reboots or chassis fails over to the standby CMC.
It is recommended that you update the standby CMC first so that there is only one failover event.
•
CMC error detection and correction — Chassis management resumes after CMC resets or chassis fails over to the
standby CMC.
NOTE: You can configure the enclosure either with a single CMC or with redundant CMCs. In redundant CMC
configurations, if the primary CMC loses communication with the enclosure or the management network, the
standby CMC takes over chassis management.
Active CMC Election Process
There is no difference between the two CMC slots; that is, slot does not dictate precedence. Instead, CMC that is
installed or booted first assumes the role of the active CMC. If AC power is applied with two CMCs installed, CMC
installed in CMC chassis slot 1 (the left) normally assumes the active role. The active CMC is indicated by the blue LED.
If two CMCs are inserted into a chassis that is already powered on, automatic active/standby negotiation can take up to
two minutes. Normal chassis operation resumes when the negotiation is complete.
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