HP-UX vPars and Integrity VM V6.3 Administrator Guide

Figure 10 Bad virtual device allocation
Supported
Virtualization Services Platform (VSP)
X
Guest 1 Guest 2
Virtual Lv Disk
As these examples illustrate, it is important to know where storage is allocated from to avoid data
getting damaged with vPars, VMs, or even the VSP. Management utilities such as the HP SMH
utility allows you to track disk devices, volume groups, logical volumes, and file systems. You can
use these utilities to annotate devices so that VSP administrators can know the vPars or VMs that
are using each VSP storage device.
To show each disk only once, management utilities consolidate multipath devices into one disk.
When you are dividing up the disk, you must use all the parts of a single disk on a single VM.
Allocating different parts of the same disk to different VMs makes it difficult to manage and to
isolate problems.
When an LVM volume group is deactivated, the physical volumes used by that storage is designated
as unused by HP-UX system administration tools such as HP SMH. This is also true for Integrity VM
storage management. As a result, these physical volumes are not automatically protected from use
by VMs as virtual disks.
You can resolve this problem in one of the following ways:
• If the volume group is to remain deactivated, the VSP administrator can manually add the
physical volume as a restricted device using the hpvmdevmgmt command.
• After activating the volume group, run the hpvmhostrdev command so that the VSP storage
management database is updated accordingly.
An HP-UX system administrator can deactivate a volume group using the vgchange command. It
can also be deactivated, if it is a shared LVM (SLVM) volume group whenever the associated
Serviceguard cluster is reconfigured, or the VSP system is rebooted. You must verify that all SLVM
volume groups are activated after a VSP reboot or Serviceguard cluster reconfiguration.
vPars and Integrity VM checks the present physical configuration when you create a vPar or VM
using the hpvmcreate command. If the vPar or VM uses backing stores that are not available,
the vPar or VM is created, and warning messages provide additional details. If you use the
hpvmstart command to start a vPar or VM that requires physical resources that are not available
on the VSP, the vPar or VM is not allowed to start, and error messages provide detailed information
about the problem.
72 Storage devices