System information

This configuration provides two paths from each HBA, so that each element of the connection can fail over to
a redundant path. The order of the paths in this configuration provides HBA and switch failover without the
need to trigger SP failover. The storage processor that the preferred paths are connected to must own the LUNs.
In the preceding example configuration, SP1 owns them.
NOTE The preceding example assumes that the switches are not connected through an Inter-Switch Link (ISL)
in one fabric.
Verify the Storage Processor Port Configuration
You can verify the SP port configuration by comparing the vSphere Client information with the information
in the DS4800 subsystem profile.
Procedure
1 Connect to the ESX/ESXi host by using the vSphere Client.
2 Select the host and choose the Configuration tab.
3 Click Storage Adapters in the Hardware panel.
4 Select each storage adapter to see its WWPN.
5 Select Storage to see the available datastores.
Compare the WWPN information to the information listed in the DS4800 storage subsystem profile.
Disabling Auto Volume Transfer
To avoid the possibility of path thrashing, disable Auto Volume Transfer (AVT) on the SAN storage processors.
If AVT is enabled, the two storage processors can alternately take ownership of the LUN in certain situations,
resulting in performance degradation. AVT is also known as ADT (Auto Disk Transfer).
To disable AVT, in the DS 4800 Storage Manager, for each port defined in each host group that contains HBAs
for one or more ESX/ESXi machines, set the host type to LNXCL or, in later versions, to VMware.
You must reboot the ESX/ESXi host after you change the AVT configuration.
Chapter 4 Setting Up SAN Storage Devices with ESX/ESXi
VMware, Inc. 37