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Write Cache Disabled on Sun StorageTek 6540 Arrays After Losing One AC Power Input (Doc ID 1398972.1)

Last updated on JULY 27, 2019

Applies to:

Sun Storage 6540 Array - Version Not Applicable to Not Applicable [Release N/A]
Information in this document applies to any platform.


The Sun StorageTek 6540 Cache will be disabled if AC power is lost to one of the two Power Supplies. This will result in a performance impact until AC power source to the affected Power Supply is restored.
This behavior is not documented in the documentation and can cause confusion as loosing one of the AC power inputs is typically not associated with having a disabled cache.

In Sun Storage Common Array Manager (CAM) several alarms will be received and both Batteries will get the Status "Unknown" and the Major Event log (MEL) will contain a line stating that the cache is disabled.

Alarm example from the CAM Browser User Interface (BUI):


This can happen either by a AC Power Cord being not properly seated or a problem with the AC power source itself .


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