Owners Manual

NOTE: It is recommended that you isolate chassis management from the data network. Dell cannot support or
guarantee uptime of a chassis that is improperly integrated into your environment. Due to the potential of traffic on
the data network, the management interfaces on the internal management network can be saturated by traffic
intended for servers. This results in CMC and iDRAC communication delays. These delays may cause unpredictable
chassis behavior, such as CMC displaying iDRAC as offline even when it is up and running, which in turn causes other
unwanted behavior. If physically isolating the management network is impractical, the other option is to separate
CMC and iDRAC traffic to a separate VLAN. The CMC and individual iDRAC network interfaces can be configured to
use a VLAN with the racadm setniccfg command. For more information, see the Dell Chassis Management
Controller Administrator Reference Guide at support.dell.com/manuals.
CMC Fail-Safe 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
• existing blades cannot be accessed 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:
Condition
Description
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 the 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 the 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. For more
information on updating the CMC firmware, see the CMC User's Guide at support.dell.com/manuals.
CMC error
detection and
correction
Chassis management resumes after the CMC resets or chassis fails over to the standby CMC.
NOTE: You can configure the enclosure 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.
Daisy-Chain CMC Network Connection
Each CMC has two RJ-45 Ethernet ports, labeled GB (the uplink port) and STK (the stacking or cable consolidation port). With basic
cabling, you can connect the GB port to the management network and leave the STK port unused.
CAUTION:
Connecting the STK port to the management network can have unpredictable results. Cabling GB and STK to
the same network (broadcast domain) can cause a broadcast storm.
If you have multiple chassis in a rack, you can reduce the number of connections to the management network by daisy-chaining up to four
chassis together. If each of the four chassis contains a redundant CMC, by daisy-chaining you can reduce the number of management
network connections required from eight to two. If each chassis has only one CMC, you can reduce the connections required from four to
one.
When daisy-chaining chassis together, GB is the uplink port and STK is the stacking (cable consolidation) port. Connect the GB ports to
the management network or to the STK port of the CMC in a chassis that is closer to the network. You must connect the STK port only
to a GB port further from the chain or network.
18
About your system