Managing Paths
To maintain a
constant connection between an
ESXi
host and
its storage,
ESXi
supports
multipathing. With multipathing you can use more than one physical path for
transferring data between the
ESXi
host and
the external storage device.
In case of failure of an element
in the SAN network, such as an HBA, switch, or cable, the
ESXi
host can
fail over to another physical path. On some devices, multipathing also offers
load balancing, which redistributes I/O loads between multiple paths to reduce
or eliminate potential bottlenecks.
The storage architecture supports a special VMkernel
layer, Pluggable Storage Architecture (PSA). The PSA is an open modular framework that
coordinates the simultaneous operation of multiple multipathing plug-ins (MPPs). You can
manage PSA by using ESXCLI commands. See Managing Third-Party Storage Arrays. This
section assumes you are using only PSA plug-ins included in vSphere by default.