A migration policy specifies whether you want to enable vMotion migration for
Flash Accel-enabled VMs, and the
migration scope: the potential target hosts for cached VMs. You might target all the hosts in a cluster, for example, or all the hosts in a datacenter.
After you select a migration policy, the amount of cache space you can allocate to a VM is limited not only by the cache space available on its host, but also by the cache space available on each migration target. So if the VM resides on host X, with 100 GB of unallocated cache, and host Y and host Z are both potential migration targets, with 75 GB and 50 GB of unallocated cache, respectively, the maximum cache space you can allocate to the VM is 50 GB. If you allocate 50 GB of cache to the VM, you will see the Cache Used field for all three hosts increase by 50 GB.
A migration policy specifies whether you want to enable vMotion migration for
Flash Accel-enabled VMs, and the
migration scope: the potential target hosts for cached VMs. You might target all the hosts in a cluster, for example, or all the hosts in a datacenter. Select the migration policy before allocating cache to VMs. You can override the policy for a given VM after allocating cache to it.