HP Integrity VM 4.3 N-Port ID Virtualization - A brief overview

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Migrating VMs with NPIV HBAs
Starting with the version 4.3, January 2012 patch release, HP Integrity VM supports the migration of VMs that include
NPIV HBAs. This includes both online and offline migration.
The requirements for migrating a VM are unchanged from previous releases. All resources used by the VM must be
available on both the source and target host.
If the VM includes NPIV HBAs (vHBAs), then the target host must have a physical Fibre Channel HBA (PFC) to create
the vHBA on, such as “/dev/fcd0”. One important requirement is that after migration, the VM's vHBA must see the
same Fibre Channel (FC) target paths as before migration. Which FC targets are visible to a vHBA depends on the
zoning settings of the FC switch.
Therefore, hpvmmigrate will choose the target host physical Fibre Channel (PFC) port based on the following:
• The PFC on the target host must support NPIV.
• The PFC must have available NPIV entries (see Limits and Limitations, above).
• The PFCs on both the source and target host must be connected to the same Fibre Channel switch.
• The FC switch must use World-Wide-Name (WWN) based zoning, as opposed to Port zoning.
If both the source and target are connected to the same FC switch, and the FC switch uses World-Wide-Name
(WWN) based zoning, then the vHBA is guaranteed to see the same FC targets as before. This is because the
vHBA’s virtual Port WWN remains the same after migration.
To see which FC switch a PFC is connected to, use the fcmsutil command, and look for the Switch Node World Wide
Name value:
# fcmsutil /dev/fcd0
Switch Port World Wide Name = 0x200800051e0351f4
Switch Node World Wide Name = 0x100000051e0351f4
The command line interface for migrating VMs is still the same for those that include NPIV HBAs. The hpvmmigrate
command is used to perform both online and offline migration.
To migrate an offline guest VM1 from host HostA to host HostB, run the command:
# hpvmmigrate -P VM1 -h HostB
To perform online migration, use the -o option:
# hpvmmigrate -o -P VM1 -h HostB
If hpvmmigrate cannot find a matching PFC on the target host, it prints an error message stating that the NPIV device
has no match:
hpvmmigrate: ERROR (VM1): Remote message:
Device 0x50D1438FF62CBCD8,0x50D1438FF62CBCD9 has no match on this HPVM server.
If hpvmmigrate finds multiple matching PFCs on the target host, it chooses the PFC with the least number of HPVM
NPIV entries, in order to balance the NPIV HBAs evenly among the PFCs.
There are some limitations to this approach. If a VM uses two NPIV HBAs for multipathing the same LUNs, after
migration there is no guarantee that the NPIV HBAs will be on separate PFCs. They could end up configured on two
ports of the same PFC.