HP Integrity Virtual Machines 4.2.5: Release Notes

9.2.7 Unpresenting SAN Devices to Integrity VM Hosts
Unpresenting SAN devices that were configured to be used by guests causes the guest to fail to
start. If SAN devices must be unpresented, guests configured to use those devices should be
reconfigured to no longer require them. After unpresenting a device special file, remove it from
the Integrity VM Host using the following command:
rmsf –a device_special_file
The device special file can be derived from the wwid_string, obtained from the SAN appliance,
as follows:
scsimgr -p get_attr -a wwid -a device_file current all_lun | grep wwid_string
9.2.8 Host May Participate in One Online Migration at a Time
A VM Host may participate in one online migration at a time, either as a source or a target. If two
migrations are attempted at the same time, hpvmmigrate might fail quickly with an error. However,
hpvmmigrate does not always detect that a migration is in progress.
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.
9.2.9 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. 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.
9.2.10 Guests Using IPv6 Not Currently Supported for Online VM Migration
IPv6 networks are supported, so long as guests also have some IPv4 networking. Guests using IPv6
are not currently supported for Online VM Migration.
9.2.11 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.
9.2.12 Veritas Volumes Not Supported for Online VM Migration
Veritas volumes are not supported for Online VM Migration.
9.2 Known Issues and Information 91