Managing High Availability; Array Dual Pathing; Load Balancing; Cli Management Commands 1 - HP StorageWorks 300 - Virtual Library System EVA Gateway User Manual

NOTE:
You can change the user or administrator account password separately, or change both at
the same time.
NOTE:
The password can also be changed from the VLS CLI. See

Managing high availability

Array dual pathing

The VLS300 supports dual pathing to the disk arrays, which provides path balancing and transparent path
failover on the VLS300. Having followed the setup recommendations in the HP StorageWorks 300 virtual
tape libraries solutions guide and the installation instructions in this guide, each node on the VLS300 is
connected to two fabrics/zones which are each connected to the external arrays by two or more paths.
This assures that the gateway can establish two paths per LUN, each path on a separate fabric/zone.

Load balancing

For load balancing, half of the data transfer (from a specific node through a fabric to the external array)
is conducted over one path; half over a second fabric, hence another path. The paths are selected as
follows: Once configured, the device recognizes all paths to each node on the device. From all potential
preferred paths and all potential secondary paths (see
one secondary path.
NOTE:
During each reboot the device is re-analyzed and the preferred and secondary paths are reassigned.
To view the preferred path for each LUN in the Storage LUN Details:
1. In Command View VLS, select the System tab.
2.
Select Storage LUNs in the navigation tree.
3.
Select the View button for either All LUNs or the LUNs in the desired <Storage Pool #>
Summary information displays at the top of the list. Preferred and secondary paths are listed after
the summary information in the Storage LUN Details Per Node sections.
NOTE:
It may take several minutes to display this information if there are many LUNs.
88 Management
CLI Management commands.
Step 3), the array assigns one preferred path and
(Figure 55).