6.7

Table Of Contents
vMotion Across Long Distances
You can perform reliable migrations between hosts and sites that are separated by high network round-
trip latency times. vMotion across long distances is enabled when the appropriate license is installed. No
user configuration is necessary.
For long-distance migration, verify the network latency between the hosts and your license.
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The round-trip time between the hosts must be up to 150 milliseconds.
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Your license must cover vMotion across long distances.
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You must place the traffic related to transfer of virtual machine files to the destination host on the
provisioning TCP/IP stack. See Place Traffic for Cold Migration, Cloning, and Snapshots on the
Provisioning TCP/IP Stack.
vMotion Shared Storage Requirements
Configure hosts for vMotion with shared storage to ensure that virtual machines are accessible to both
source and target hosts.
During a migration with vMotion, the migrating virtual machine must be on storage accessible to both the
source and target hosts. Ensure that the hosts configured for vMotion use shared storage. Shared
storage can be on a Fibre Channel storage area network (SAN), or can be implemented using iSCSI and
NAS.
If you use vMotion to migrate virtual machines with raw device mapping (RDM) files, make sure to
maintain consistent LUN IDs for RDMs across all participating hosts.
See the vSphere Storage documentation for information on SANs and RDMs.
vSphere vMotion Networking Requirements
Migration with vMotion requires correctly configured network interfaces on source and target hosts.
Configure each host with at least one network interface for vMotion traffic. To ensure secure data transfer,
the vMotion network must be a secure network, accessible only to trusted parties. Additional bandwidth
significantly improves vMotion performance. When you migrate a virtual machine with vMotion without
using shared storage, the contents of the virtual disk is transferred over the network as well.
vSphere 6.5 allows the network traffic with vMotion to be encrypted. Encrypted vMotion depends on host
configuration, or on compatibility between the source and destination hosts.
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. These limits vary with a host's link speed to the vMotion network.
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