Enclosure failover when two emms are installed – Dell POWERVAULT MD1000 User Manual
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About Your System
Figure 1-7. Enclosure Mode Switch Settings
NOTE:
To change the enclosure mode, you must change the position of the enclosure mode switch before turning
on power to the enclosure. Changing the position of the switch while the enclosure is on will not affect enclosure
operation until the enclosure is rebooted.
For a complete description of the roles of the primary and secondary EMMs, see "Operating Your Storage
Enclosure Failover When Two EMMs are Installed
If two EMMs are installed, a certain degree of failover is offered. Control and monitoring of the enclosure
elements can be transferred from one EMM to another in the event of an EMM failure. A failover occurs
whenever communication is lost between an EMM and its peer.
In the event of a peer EMM failure, the surviving EMM activates the amber status LED of the failed
EMM and holds it in reset. The surviving EMM then takes over the responsibility of enclosure
management, which includes monitoring and control of the audible alarm, enclosure LEDs, power
supplies, and fans.
Failover does not include providing connectivity to the drives controlled by the failed EMM. When a
failed EMM is replaced, enclosure management functions do not automatically return to the replaced
EMM unless an additional failure occurs that triggers another failover event.
1
unified mode switch setting
2
split mode switch setting
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