Controller Failure Conditions; Critical Conditions; Noncritical Conditions; Invalid Storage Array - Dell EMC PowerVault MD3820i Owner's Manual

5. Close the system.
6. Run the appropriate diagnostic test. For more information, see Using System Diagnostics.
If the tests fail, see Getting

Controller failure conditions

Certain events can cause a RAID controller module to fail and/or shut down. Unrecoverable ECC memory or PCI errors, or
critical physical conditions can cause lockdown. If your RAID storage array is configured for redundant access and cache
mirroring, the surviving controller can normally recover without data loss or shutdown.

Critical conditions

The storage array generates a critical event if the RAID controller module detects a critical condition that could cause immediate
failure of the array and/or loss of data. The storage array is in a critical condition if one of the following occurs:
● More than one fan has failed
● Any midplane temperature sensors in the critical range
● Midplane/power supply module failure
● Two or more temperature sensors are unreadable
● Failure to detect or unable to communicate with peer port
NOTE: If both RAID controller modules fail simultaneously, the enclosure cannot issue critical or noncritical event alarms for
any enclosure component.

Noncritical conditions

A noncritical condition is an event or status that does not cause immediate failure, but must be corrected to ensure continued
reliability of the storage array. Examples of noncritical events include the following:
● One power supply module has failed
● One cooling fan module has failed
● One RAID controller module in a redundant configuration has failed
● A battery has failed or has been removed
● A physical disk in a redundant virtual disk has failed

Invalid Storage Array

The RAID controller module is supported only in a Dell EMC-supported storage array. After installation in the storage array, the
controller performs validation checks. The array status LED is lit with a steady amber color while the RAID controller module
completes these initial tests and the controllers are booted successfully. If the RAID controller module detects a non-Dell EMC
supported storage array, the controller does not start up. The RAID controller module does not generate any events to alert you
in the event of an invalid array, but the array status LED is lit with a flashing amber color to indicate a fault state.

ECC Errors

RAID controller firmware can detect ECC errors and can recover from a single-bit ECC error whether the RAID controller
module is in a redundant or non-redundant configuration. A storage array with redundant controllers can recover from multi-bit
ECC errors as well because the peer RAID controller module can take over, if necessary.
The RAID controller module fails over if it experiences up to 10 single-bit errors, or up to three multi-bit errors.
34 Troubleshooting Your System
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