Dell PowerEdge M420 Hardware Owner's Manual - Page 46

- The CMC supports setting an optional enclosure Maximum Power Limit, which either alerts or takes actions, such as throttling server modules and/or preventing the power up of new blades to keep the enclosure under the defined maximum power limit. - The CMC monitors and automatically controls cooling fans based on actual ambient and internal temperature measurements. - The CMC provides comprehensive enclosure inventory and status/error reporting. • The CMC provides a mechanism for centralized configuration of the following: - The M1000e enclosure's network and security settings - Power redundancy and power ceiling settings - I/O switches and iDRAC network settings - First boot device on the server blades - The CMC checks I/O fabric consistency between the I/O modules and blades and disables components if necessary to protect the system hardware. - User access security. The CMC has two Ethernet ports: Gb1 is used to connect to the external management network. The connector labeled STK ("stack") allows CMCs in adjacent enclosures to be daisy-chained. A 24-port Ethernet switch provides internal communication between the iDRAC on each blade, I/O modules, optional KVM, and optional second, redundant CMC. NOTE: The 24-port Ethernet switch is reserved for internal communication between the iDRAC on the blades to the CMC and the external management network. If two CMCs are installed, the heartbeat for CMC redundancy is also present and CMC redundancy is supported over this internal network. This internal network is outside the data path from host LOMs and the mezzanine cards in the blades. At least one CMC must be installed in the primary CMC bay (see Figure 1-19) for the system to power up. If a second, optional CMC module is installed, failover protection and hot-plug replacement is available. See the latest Dell Chassis Management Controller User's Guide at support.dell.com for complete instructions on how to set up and operate the CMC module. 46 About Your System