Dell UCPM-800 manual Configuring Multipath Support In Windows, Multipath support in Linux

Multipath Support

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 MPIO driver 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.

Configuring Multipath Support In Windows

In Windows, multipath support is enabled by installing the MPIO driver. The Shared PERC 8 device must be added to the list of devices that are aggregated by MPIO after the device driver is installed. Perform the following steps to add the Shared PERC 8 card:

1.Open the MPIO control panel.

2.Click the Discover Multi-Paths tab.

3.Select DELL Shared PERC8 and click Add.

This is only a one time setup procedure. After the Shared PERC 8 device is added to the list of devices, the MPIO driver aggregates all instances of the same virtual disk into a single one. The recommended multipath policy for Windows is round-robin (with subset).

Configuring Multipath Support In VMWare

In VMWare, multipath support is automatically enabled using Native Multipathing (NMP) for all Shared PERC 8 cards in Dell versions of the ESXi operating systems.

NOTE: The recommended multipath policy is Most Recently Used (MRU).

Multipath support in Linux

Currently, Linux support is not offered by Dell on fault tolerant VRTX configurations.

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