6.0.1

Requirements for Concurrent vMotion Migrations
You must ensure that the vMotion network has at least 250 Mbps of dedicated bandwidth per concurrent
vMotion session. Greater bandwidth lets migrations complete more quickly. Gains in throughput resulting
from WAN optimization techniques do not count towards the 250 Mbps limit.
To determine the maximum number of concurrent vMotion operations possible, see “Limits on
Simultaneous Migrations,” on page 144. These limits vary with a host's link speed to the vMotion network.
Round-Trip Time for Long-Distance vMotion Migration
If you have the proper license applied to your environment, you can perform reliable migrations between
hosts that are separated by high network round-trip latency times. The maximum supported network
round-trip time for vMotion migrations is 150 milliseconds. This round-trip time lets you migrate virtual
machines to another geographical location at a longer distance.
Multiple-NIC vMotion
You can congure multiple NICs for vMotion by adding two or more NICs to the required standard or
distributed switch. For details, see the VMware knowledge base article at hp://kb.vmware.com/kb/2007467.
Network Configuration
Congure the virtual networks on vMotion enabled hosts as follows:
n
On each host, congure a VMkernel port group for vMotion.
To have the vMotion trac routed across IP subnets, enable the vMotion TCP/IP stack on the host. See
“Place vMotion Trac on the vMotion TCP/IP Stack of an ESXi Host,” on page 141.
n
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.
N By default, you cannot use vMotion to migrate a virtual machine that is aached to a standard
switch with no physical uplinks congured, even if the destination host also has a no-uplink standard
switch with the same label.
To override the default behavior, set the
config.migrate.test.CompatibleNetworks.VMOnVirtualIntranet advanced seings of vCenter Server to
false. The change takes eect immediately. For details about the seing, see VMware knowledge base
article at hp://kb.vmware.com/kb/1003832. For information about conguring advanced seings of
vCenter Server, see “Congure Advanced Seings,” on page 48.
For information about conguring vMotion network resources, see “Networking Best Practices for vSphere
vMotion,” on page 123.
vCenter Server and Host Management
122 VMware, Inc.