6.5.1

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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.
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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.
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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.
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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 ESXi 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 will remain preferred no matter what its status is.
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By default, the PSA claim rule 101 masks Dell array pseudo devices. Do not delete this rule, unless
you want to unmask these devices.
List Multipathing Claim Rules for the Host
Use the esxcli command to list available multipathing claim rules.
Claim rules indicate whether the NMP multipathing plug-in or a third-party MPP manages a given physical
path. Each claim rule identifies a set of paths based on the following parameters:
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Vendor/model strings
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Transportation, such as SATA, IDE, Fibre Channel
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Adapter, target, or LUN location
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Device driver, for example, Mega-RAID
In the procedure, --server=server_name specifies the target server. The specified target server
prompts you for a user name and password. Other connection options, such as a configuration file or
session file, are supported. For a list of connection options, see Getting Started with vSphere Command-
Line Interfaces.
Prerequisites
Install vCLI or deploy the vSphere Management Assistant (vMA) virtual machine. See Getting Started with
vSphere Command-Line Interfaces. For troubleshooting, run esxcli commands in the ESXi Shell.
vSphere Storage
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