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

Figure 17 (page 197) shows moving a guest online from a source VSP to a target VSP.
Figure 17 Online VM migration from source to target
Guest 1
Source VSP
Guest OS with:
Unique Kernel Parameters
Patch Levels
Layered Software
Guest continues to operate on
Source VSP (including apps)
while migration begins
Guest is briefly
suspended as
final resident memory image transfers
online
Target VSP
Guest 2
Guest OS with:
Unique Kernel Parameters
Patch Levels
Layered Software
1 3
Guest continues operation on
Target VSP (including apps) after
transfer completes
2
SAN
NOTE: Online migration is supported only in the case of VM guests. You cannot migrate a vPar
using the Online migration process.
12.1.1 Considerations for migrating an online VM
Following are the considerations to migrate an online VM:
Vacating a VSP system — With OVMM, you can migrate all VMs from a VSP to one or more
VSPs without interrupting the workload activity on the VM. This is most often done for the
maintenance of the VSP system — hardware, firmware, or software. You can configure the
hardware that does not have hot-plug support. You can update the firmware, which requires
the system to be shut down. You can also update software components that require a VSP
reboot. A rolling upgrade of VSP software is possible by moving the running guests to another
VSP, upgrading the VSP, and then migrating the guests back. Moving VMs while keeping
active applications online allows greater flexibility in scheduling maintenance or upgrades,
and minimizes the impact of unpredictable maintenance. For example, you can move online
VMs in response to predictive failure alerts without interrupting your applications.
Targeting a particular VSP You might want to migrate an active VM workload to a particular
VSP to take advantage of a particular resource or feature on that target VSP without losing
application availability. If your current VSP resources become oversubscribed, you can migrate
one or more of the VMs to other VSPs that have the remaining capacity. A potential target
VSP might have a large quantity of RAM, CPUs, or I/O adapters, which might facilitate faster
processing or greater I/O bandwidth while on that VSP. Another possibility is that, certain
VSPs have special devices that are needed only temporarily by VM workloads. Because
OVMM enables VMs to be migrated without interrupting their workloads, it is convenient and
practical to migrate VMs temporarily to certain VSPs to take advantage of particular resources
12.1 Introduction to migration 197