Home > Storage > PowerMax and VMAX > Data Protection > Dell PowerMax: Reliability, Availability, and Serviceability > PowerMax NVMe back end
The PowerMax architecture incorporates an NVMe back end that reduces command latency and increases data throughput while maintaining full redundancy. NVMe is an interface that allows host software to communicate with a nonvolatile memory subsystem. This interface is optimized for Enterprise and Client solid-state drives (SSDs), typically attached as a register-level interface to the PCI Express interface.
The NVMe back-end subsystem provides redundant paths to the data stored on solid-state drives. This provides seamless access to information, even in the event of a component failure or replacement.
Each PowerMax Drive Array Enclosure (DAE) can hold 24 x 2.5” NVMe SSDs. The DAE also houses redundant Canister Modules (Link Control Cards) and redundant AC/DC power supplies with integrated cooling fans. Figure 9 and Figure 10 show the front and back views of the PowerMax DAE.
The directors are connected to each DAE through a pair of redundant back-end I/O modules. The back-end I/O modules connect to the DAEs at redundant LCCs. Each connection between a back-end I/O module and an LCC uses a completely independent cable assembly. Within the DAE, each NVMe drive has two ports, each of which connects to one of the redundant LCCs.
The dual-initiator feature ensures continuous availability of data in the unlikely event of a drive management hardware failure. Both directors within an engine connect to the same drives using redundant paths. If the sophisticated fencing mechanisms of PowerMaxOS detect a failure of the back-end director, the system can process reads and writes to the drives from the other director within the engine without interruption.