Storage Array Type Plug-ins (SATPs) are responsible for array-specific operations. The SATPs are submodules of the VMware NMP.

ESXi offers an SATP for every type of array that VMware supports. ESXi also provides default SATPs that support non-specific active-active, active-passive, ALUA, and local devices.

Each SATP accommodates special characteristics of a certain class of storage arrays. The SATP can perform the array-specific operations required to detect path state and to activate an inactive path. As a result, the NMP module itself can work with multiple storage arrays without having to be aware of the storage device specifics.

Generally, the NMP determines which SATP to use for a specific storage device and associates the SATP with the physical paths for that storage device. The SATP implements the tasks that include the following:

  • Monitors the health of each physical path.
  • Reports changes in the state of each physical path.
  • Performs array-specific actions necessary for storage fail-over. For example, for active-passive devices, it can activate passive paths.
ESXi includes several generic SATP modules for storage arrays.
VMW_SATP_LOCAL
SATP for local direct-attached devices.
As of vSphere 6.5 Update 2 release, VMW_SATP_LOCAL provides multipathing support for the local devices, except the devices in 4K native format. To claim multiple paths to the local devices, you are no longer required to use other SATPs as you were in the earlier vSphere releases.
VMW_SATP_LOCAL supports the VMW_PSP_MRU and VMW_PSP_FIXED path selection plug-ins, but does not support VMW_PSP_RR.
VMW_SATP_DEFAULT_AA
Generic SATP for active-active arrays.
VMW_SATP_DEFAULT_AP
Generic SATP for active-passive arrays.
VMW_SATP_ALUA
SATP for ALUA-compliant arrays.

For more information, see the VMware Compatibility Guide and the ESXCLI Reference documentation.

Display SATPs for the Host

Use the esxcli command to list VMware NMP SATPs loaded into the system. Display information about the SATPs.

Prerequisites

Install ESXCLI. See Getting Started with ESXCLI. For troubleshooting, run esxcli commands in the ESXi Shell.

Procedure

  • ♦ To list VMware SATPs, run the following command:
    esxcli storage nmp satp list

Results

For each SATP, the output displays information that shows the type of storage array or system the SATP supports. The output also shows the default PSP for any LUNs that use this SATP. Placeholder (plugin not loaded) in the Description column indicates that the SATP is not loaded.

Example: Displaying SATPs for the Host

# esxcli storage nmp satp list
Name                 Default PSP    Description
VMW_SATP_MSA         VMW_PSP_MRU    Placeholder (plugin not loaded)
VMW_SATP_ALUA        VMW_PSP_MRU    Placeholder (plugin not loaded)
VMW_SATP_DEFAULT_AP  VMW_PSP_MRU    Placeholder (plugin not loaded)
VMW_SATP_SVC         VMW_PSP_FIXED  Placeholder (plugin not loaded)
VMW_SATP_EQL         VMW_PSP_FIXED  Placeholder (plugin not loaded)
VMW_SATP_INV         VMW_PSP_FIXED  Placeholder (plugin not loaded)
VMW_SATP_EVA         VMW_PSP_FIXED  Placeholder (plugin not loaded)
VMW_SATP_ALUA_CX     VMW_PSP_RR     Placeholder (plugin not loaded)
VMW_SATP_SYMM        VMW_PSP_RR     Placeholder (plugin not loaded)
VMW_SATP_CX          VMW_PSP_MRU    Placeholder (plugin not loaded)
VMW_SATP_LSI         VMW_PSP_MRU    Placeholder (plugin not loaded)
VMW_SATP_DEFAULT_AA  VMW_PSP_FIXED  Supports non-specific active/active arrays
VMW_SATP_LOCAL       VMW_PSP_FIXED  Supports direct attached devices

For more information about the command, see the ESXCLI Concepts and Examples and ESXCLI Reference documentation.