HP Integrity Virtual Machines Installation, Configuration, and Administration

Each multipath software solution for HP-UX 11.23 interacts at different layers on the I/O stack.
Since Integrity VM also interacts with different layers in the I/O stack, only certain options apply
to each virtual media type.
Table 7-1 lists the multipath solutions to use on a VM Host for each type of virtual storage media:
Table 7-1 Multipath Solutions
Multipath OptionsVirtual Media Type
EMC PowerPath
HP Autopath/SecurePath
Whole Disk
PVLinks
EMC PowerPath
HP Autopath/SecurePath
LVM Logical Volume
EMC PowerPath
HP Autopath/SecurePath
VxVM Logical Volume
PVLinks
EMC PowerPath
HP Autopath/SecurePath
VxFS File System
Although Table 7-1 lists the possible solutions for each virtual media type, it cannot determine
what is supported on your specific VM Host configuration. Each multipath solution is only
supported for specific hardware and software. The solution vendors provide this information
for their multipath products. Review the installation and release notes of these products carefully
to form a valid VM Host configuration before using it for any virtual machine. Some multipath
options do not work together and they all have different load balancing features.
7.2.1.4 VM Storage Management
Before you decide how to divide VM Host storage, consider the impact on the management of
the storage subsystem.
A VM Host administrator manages VM storage to make sure virtual media is allocated safely.
This begins with understanding the VM Host I/O stack and knowing where the virtual media is
being allocated from.
Figure 7-3 shows an example of a VM Host I/O stack as it applies to a single LUN:
Figure 7-3 Sub-LUN Storage Allocation Example
File File File File File File File File
2 2
Logical Volume Logical Volume Logical Volume Logical Volume
Whole Disk
1
2
The virtual machine is allocated a logical volume from the LUN for a Virtual LvDisk.
The logical volume that has been allocated is marked 1.
The parts of the disk that cannot be allocated are marked 2.
Those parts that are no longer available include the files that were on the logical volume and the
whole disk that makes up part of the volume group. If any of these parts are allocated for other
virtual devices, data corruption can occur on the Virtual LvDisk.
Those parts that are still available for reallocation include other logical volumes that are on the
disk,and files that are on those other logical volumes on the disk. These pieces can be allocated
without data corruption problems because they do not overlap with the Virtual LvDisk.
78 Creating Virtual Storage Devices