CX700 SPE Power Supply Failure Write Disabled?

Shane,
During the loss/fault of a Power Supply in the base enclosure, Write Cache will be temporarily disabled. This is to ensure data protection, in the event that the other Power Supply in the same enclosure should also fail. Consistent with what you noted, read and write access is still provided to all data. Write Cache will automatically re-enable once the loss/fault condition with the Power Supply is corrected (e.g. a faulty one is replaced).

Please note that the above only applies to "the base enclosure". This refers to the enclosure that holds the two Storage Processors, and the enclosure that holds the first 15 drives. Depending on the specific CX model, that may be one or two physical entities (e.g. a DPE, or an SPE plus the DAE for Bus 0 Enclosure 0).

Regards,
DGM

The only thing I would add (or clarify) would be that I think there is a delay between the replacement of the failed power supply and the actual enabling of write cache.

If I'm not mistaken, once power is restored the SPS begins charging and the write cache is not enabled until the SPS is fully charged. This might be as much as 15 minutes sometimes.

So if you restore power and check immediately it will look like the write cache did NOT get automatically turned back on.