Specifications

vMotion Networking Requirements
Migration with vMotion requires correctly configured network interfaces on source and target hosts.
vMotion requires a Gigabit Ethernet (GigE) network between all vMotion-enabled hosts. Each host enabled
for vMotion must have a minimum of two Ethernet adapters, at least one of which must be a GigE adapter.
Recommended networking best practices are as follows:
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Use one dedicated GigE adapter for vMotion.
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If only two Ethernet adapters are available:
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For best security, dedicate the GigE adapter to vMotion, and use VLANs to divide the virtual machine
and management traffic on the other adapter.
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For best availability, combine both adapters into a bond, and use VLANs to divide traffic into
networks: one or more for virtual machine traffic and one for vMotion.
Configure the virtual networks on vMotion-enabled hosts as follows:
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On each host, configure a VMkernel port group for vMotion.
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Ensure that virtual machines have access to the same subnets on source and destination hosts.
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If you are using standard switches for networking, ensure that the network labels used for virtual machine
port groups are consistent across hosts. During a migration with vMotion, vCenter Server assigns virtual
machines to port groups based on matching network labels.
NOTE You cannot migrate virtual machines that are attached to a virtual intranet with vMotion, even if
the destination host has a virtual intranet configured with the same network label.
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If you are using vSphere Distributed Switches for networking, ensure that source and destination hosts
are members of all vSphere Distributed Switches that virtual machines use for networking.
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Use of Jumbo Frames is recommended for best vMotion performance.
Virtual Machine Configuration Requirements for vMotion
A number of specific virtual machine configurations can prevent migration of a virtual machine with vMotion.
The following virtual machine configurations can prevent migration with vMotion:
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You cannot use migration with vMotion to migrate virtual machines using raw disks for clustering
purposes.
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You cannot use migration with vMotion to migrate a virtual machine that uses a virtual device backed by
a device that is not accessible on the destination host. (For example, you cannot migrate a virtual machine
with a CD drive backed by the physical CD drive on the source host.) Disconnect these devices before
migrating the virtual machine.
Virtual machines with USB passthrough devices can be migrated with vMotion as long as the devices are
enabled for vMotion.
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You cannot use migration with vMotion to migrate a virtual machine that uses a virtual device backed by
a device on the client computer. Disconnect these devices before migrating the virtual machine.
vCenter Server and Host Management
114 VMware, Inc.