If no SATP is assigned to the device by the claim rules, the default SATP for iSCSI or FC devices is

VMW_SATP_DEFAULT_AA

. The default PSP is

VMW_PSP_FIXED

.

When the system searches the SATP rules to locate a SATP for a given device, it searches the driver rules first. If there is no match, the vendor/model rules are searched, and finally the transport rules are searched. If no match occurs, NMP selects a default SATP for the device.

If

VMW_SATP_ALUA

is assigned to a specific storage device, but the device is not ALUA-aware, no claim rule match occurs for this device. The device is claimed by the default SATP based on the device's transport type.

The default PSP for all devices claimed by

VMW_SATP_ALUA

is

VMW_PSP_MRU

. The

VMW_PSP_MRU

selects an active/optimized path as reported by the

VMW_SATP_ALUA

, or an active/unoptimized path if there is no active/optimized path. This path is used until a better path is available (MRU). For example, if the

VMW_PSP_MRU

is currently using an active/unoptimized path and an active/optimized path becomes available, the

VMW_PSP_MRU

will switch the current path to the active/optimized one.

While

VMW_PSP_MRU

is typically selected for ALUA arrays by default, certain ALUA storage arrays need to use

VMW_PSP_FIXED

. To check whether your storage array requires

VMW_PSP_FIXED

, see the

VMware Compatibility Guide

or contact your storage vendor. When using

VMW_PSP_FIXED

with ALUA arrays, unless you explicitly specify a preferred path, the

host selects the most optimal working path and designates it as the default preferred path. If the host selected path becomes unavailable, the host selects an alternative available path. However, if you explicitly designate the preferred path, it remains preferred no matter what its status is.

By default, the PSA claim rule 101 masks Dell array pseudo devices. Do not delete this rule, unless you want to unmask these devices.