Dell PowerFlex 4.5.x Technical Overview

Physical layer

This section describes the PowerFlex physical layer and outlines the steps for implementing it.

The physical layer consists of the hardware (servers with storage devices and the network between them) and the software that is installed on them.

Typically, each SDS is physically on a separate server.

To implement the physical layer, perform the following steps:

1. Install the MDM component on the MDM nodes in one of the following configurations:

   • Three-node redundant cluster (one primary MDM, one secondary MDM, and one tiebreaker).
   • Five-node redundant cluster (one primary MDM, two secondary MDMs, and two tiebreakers).
   • Single node (one primary MDM).
     NOTE:It is not recommended to use single mode in production systems, except in temporary situations. The MDM contains all the metadata required for system operation. Single Mode has no protection, and exposes the system to a single point of failure.

     MDMs do not require dedicated nodes. They can be installed on nodes hosting other PowerFlex components.

2. Install the SDS component on all nodes that contributes some, or all, of their physical storage.
   • Divide the SDS nodes into protection domains. Each SDS can be a member of only one protection domain.
   • Per protection domain, divide the physical storage units into storage pools, and optionally, into fault sets.
3. Install the SDC component on all nodes on which the application accesses the data exposed by the PowerFlex volumes.
   • In the following figure, the gray boxes represent a storage node which hosts the SDS, SDC, and MDM where applicable. In the cases where the gray boxes host the SDS, SDC, and MDM it is a three-node MDM cluster.

   
   
   

Communication is done over the existing LAN using standard TCP/IP. The MDM and SDS nodes can be assigned to up to eight IP addresses, enabling wider bandwidth and better I/O performance and redundancy.