Integrity VM virtual devices support only the built-in multipathing of the HP-UX 11i v3 VM Host, which is enabled by default to provide improved performance, load-balancing, and higher availability for VMs. Currently, there are no multipath solutions supported for the attachable device types of tapes, media changers, and CD/DVD burners.
There are no multiple paths inside a virtual machine to virtual devices. Multipathing is supported only on the VM Host for the following reasons:
The VM Host is the only place where all virtual I/O can be properly load balanced for the best overall performance. A single virtual machine cannot account for all the other virtual machine I/O with which it is competing on the VM Host (see Figure 7-1).
Running a multipath solution in a virtual machine does not provide any high availability for a virtual device. Virtual connections between virtual adapters and their devices are never lost until an hpvmmodify command is used to disconnect them. The only connection ever lost is the ability of a virtual device to access its own virtual media through the VM Host. Errors in communication to the virtual media are properly emulated as media errors sent to the guest OS, not as path failures.
The VM Host does not return specific errors to Integrity VM for hardware path failures. Integrity VM does not detect such events and does not pass them to the virtual machine.
