6.7

Table Of Contents
As the Pluggable Storage Architecture illustration shows, multiple third-party MPPs can run in parallel with
the VMware NMP or HPP. When installed, the third-party MPPs can replace the behavior of the native
modules. The MPPs can take control of the path failover and the load-balancing operations for the
specified storage devices.
Figure 185. Pluggable Storage Architecture
Pluggable Storage Architecture
VMKernel
Third-party
MPP
Third-party
MPP
VMware NMP
VMware SATP
VMware SATP
VMware SATP
Third-party SATP
VMware PSP
VMware PSP
Third-party PSP
VMware
HPP
VMware Native Multipathing Plug-In
By default, ESXi provides an extensible multipathing module called Native Multipathing Plug-In (NMP).
Generally, the VMware NMP supports all storage arrays listed on the VMware storage HCL and provides
a default path selection algorithm based on the array type. The NMP associates a set of physical paths
with a specific storage device, or LUN.
For additional multipathing operations, the NMP uses submodules, called SATPs and PSPs. The NMP
delegates to the SATP the specific details of handling path failover for the device. The PSP handles path
selection for the device.
Typically, the NMP performs the following operations:
n
Manages physical path claiming and unclaiming.
n
Registers and de-registers logical devices.
n
Associates physical paths with logical devices.
n
Supports path failure detection and remediation.
n
Processes I/O requests to logical devices:
n
Selects an optimal physical path for the request.
n
Performs actions necessary to handle path failures and I/O command retries.
n
Supports management tasks, such as reset of logical devices.
ESXi automatically installs an appropriate SATP for an array you use. You do not need to obtain or
download any SATPs.
vSphere Storage
VMware, Inc. 209