HP Integrity Virtual Machines Version 4.2 Release Notes

In most cases, migrating a guest saturates a 1 GB network. Migrating more than one guest at a
time on a network usually takes longer than migrating them sequentially, and the guest frozen
phase is longer as well.
Do not attempt to migrate more than one guest at a time on a single VM Host or network.
9.2.8 Online Migration on the Target VM Host is the Same as Starting the Guest on
the Target VM Host
Online migration on the target VM Host system is equivalent to starting the guest on the target
VM Host. The same locks are required to safely start the guest on the target VM Host system.
These locks assure that a starting guest can allocate all the resources if requires. Only one guest
start can occur at any one time. Therefore, while an online migration is being performed on the
target, no other guest starts can proceed, because it could take away resources that are required
by the migrating guest.
9.2.9 Guests Using Only IPv6 Not Currently Supported for Online VM Migration
IPv6 networks are supported, so long as guests also have some IPv4 networking. Guests using
only IPv6 are not currently supported for Online VM Migration.
9.2.10 Transient Network Errors Can Cause hpvmmigrate Connectivity Check
Failures
A transient network error might cause the hpvmmigrate command's vswitch connectivity check
to report a failure. If the connectivity check fails, retry the migration by re-issuing the
hpvmmigrate command.
If the hpvmmigrate command's network connectivity check continues to fail, verify the vswitch
and network configuration, and test connectivity with the nwmgr command as explained in
Section 10.3 of the HP Integrity Virtual Machines 4.2: Installation, Configuration, and Administration
manual.
If the vswitch connectivity required by the guest on the target VM Host is properly configured
and verified, you can use the hpvmmigrate -w option to bypass vswitch connectivity checks.
9.2.11 Veritas Volumes Not Supported for Online VM Migration
Veritas volumes are not supported for Online VM Migration.
9.2.12 Storage for Deactivated Volume Groups not Protected by Integrity VM Storage
Management
When an LVM volume group is deactivated, the storage (physical volumes) used by that storage
is designated as unused by HP-UX system administration tools such as System Management
Homepage (SMH). This is also true for Integrity VM storage management. As a result, these
physical volumes are not automatically protected from use by virtual machines as virtual disks.
You can resolve this problem in one of two way:
• If the volume group is to remain deactivated, the VM Host administrator can manually add
the physical volume as a restricted device with the hpvmdevmgmt command.
• Or, after activating the volume group, execute the hpvmhostrdev command, so that the
VM Host 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 VM Host system is rebooted. Take care to check that
all SLVM volume groups are activated after a VM Host reboot or Serviceguard cluster
reconfiguration.
9.2 Known Issues and Information 85