Hardware Details; Data Unavailable (Du); All Configurations; Promo Code 1 - EMC ATMOS Hardware Manual

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Hardware Details

Data Unavailable (DU)

A failure on most system components causes a Data Unavailable (DU) until the component is replaced.
This section describes general operating behavior with respect to DU conditions.
Atmos software tolerates failed components, and depending on the customer's policy, the loss or one or
more components would not make data unavailable at the system level. For example, if there are three
replicas and one fails, the customer's data would still be available.

All Configurations

There is one server connected to the DAEs; there is no HA path.
The SAS cables contain four lanes of SAS communication.
The DAEs contain a single LCC board with no hardware failover capabilities.
Promo Code 1
All components in the system contain one power supply.
Any power supply failure causes a DU.
The SAS cables to the DAEs are serially chained.
A failure on the rear DAE causes a DU on the entire server.
The switches also could be a single‐point failure which causes a DU. The switches do have
redundant, field‐replaceable power supplies.
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