vSphere Storage - ESXi 5.1 - Documentation - VMware

3 Click Devices under View.
4 Select the storage device whose paths you want to view and click Manage Paths.
5 In the Paths panel, select the path to view.
The panel underneath displays the path's name. The name includes parameters describing the path:
adapter ID, target ID, and device ID.
6 (Optional) To extract the path's parameters, right-click the path and select Copy path to clipboard.
View Storage Device Paths in the vSphere Web Client
View which multipathing policies the host uses for a specific storage device and the status of all available paths
for this storage device.
Procedure
1 Browse to the host in the vSphere Web Client navigator.
2 Click the Manage tab, and click Storage.
3 Click Storage Devices.
4 Select the storage device whose paths you want to view.
5 Click the Properties tab and review details under Multipathing Policies.
6 Click the Paths tab to review all paths available for the storage device.
Setting a Path Selection Policy
For each storage device, the ESXi host sets the path selection policy based on the claim rules.
By default, VMware supports the following path selection policies. If you have a third-party PSP installed on
your host, its policy also appears on the list.
Fixed (VMware) The host uses the designated preferred path, if it has been configured.
Otherwise, it selects the first working path discovered at system boot time. If
you want the host to use a particular preferred path, specify it manually. Fixed
is the default policy for most active-active storage devices.
Most Recently Used
(VMware)
Chapter 20 Understanding Multipathing and Failover
NOTE If the host uses a default preferred path and the path's status turns to
Dead, a new path is selected as preferred. However, if you explicitly designate
the preferred path, it will remain preferred even when it becomes inaccessible.
The host selects the path that it used most recently. When the path becomes
unavailable, the host selects an alternative path. The host does not revert back
to the original path when that path becomes available again. There is no
preferred path setting with the MRU policy. MRU is the default policy for most
active-passive storage devices.
Round Robin (VMware) The host uses an automatic path selection algorithm rotating through all active
paths when connecting to active-passive arrays, or through all available paths
when connecting to active-active arrays. RR is the default for a number of arrays
and can be used with both active-active and active-passive arrays to implement
load balancing across paths for different LUNs.
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