When you migrate a powered on virtual machine from one host to another, you can specify whether or not to migrate Flash Read Cache contents with the virtual disks.


If you plan to migrate Flash Read Cache contents, configure a sufficient virtual flash resource on the destination host.


  1. Right-click the running virtual machine and select Migrate.
  2. Specify the migration type.
    Option Description
    Change compute resource only Migrate the virtual machines to another host or cluster.
    Change both compute resource and storage Migrate the virtual machines to a specific host or cluster and their storage to a specific datastore or datastore cluster.
  3. Select the destination host and click Next.
  4. Specify a migration setting for all virtual disks configured with virtual Flash Read Cache. This migration parameter does not appear when you do not change the host, but only change the datastore.
    Flash Read Cache Migration Settings Description
    Always migrate the cache contents Virtual machine migration proceeds only if all of the cache contents can be migrated to the destination host. This option is useful when the cache is small or the cache size closely matches the application's active data.
    Do not migrate the cache contents Deletes the write-through cache. Cache is recreated on the destination host. This option is useful when the cache size is large or the cache size is larger than the application's active data.
  5. If you have multiple virtual disks with Flash Read Cache, you can adjust the migration setting for each individual disk.
    1. Click Advanced.
    2. Select a virtual disk for which you want to modify the migration setting.
    3. From the drop-down menu in the Virtual Flash Read Cache Migration Setting column, select an appropriate option.
  6. Complete your migration configuration and click Finish.

What to do next

Verify the successful migration by looking at the Summary tab of the virtual machine:
  • Make sure that the tab displays the correct IP address of the destination host.
  • Make sure that the VM Hardware panel displays correct Virtual Flash Read Cache information for each virtual disk.