Dell Shared PowerEdge RAID Controller (PERC) 8 For Dell PowerEdge VRTX Systems User’s Guide

Multipathing solutions use redundant physical path components such as adapters, cables, and switches to create logical paths between the server and the storage device. In the event that one or more of these components fails, multipathing logic uses an alternate path for I/O so that applications can still access their data.

In the Fault Tolerant Shared PERC 8 card configuration, the PowerEdge VRTX system has two Shared PERC 8 cards in an active-passive mode. In this configuration, each host server can access the same virtual disk through both cards. In the absence of a multipath driver, the operating system identifies the single disk as two identical disks. The multipath driver aggregates the two disks into a single disk with redundant access that is then presented to the operating system. The operating system’s multipath functionality determines the path chosen for any I/O sent to the virtual disk. Any I/O directed to the passive card is internally redirected to the active card for completion.

For instructions on how to set up multipath for supported operating systems, see Multipath and clustering setup