6.5.1

Failed Attempts to Migrate VMs with Memory Snapshots to and
from Virtual Datastores
When you attempt to migrate a VM with hardware version 10 or earlier to and from a vSphere Virtual
Volumes datastore, failures occur if the VM has memory snapshots.
Problem
The following problems occur when you migrate a version 10 or earlier VM with memory snapshots:
n
Migration of a version 10 or earlier VM with memory snapshots to a virtual datastore is not supported
and causes a failure.
n
Migration of a version 10 or earlier VM with memory snapshots from a virtual datastore to a nonvirtual
datastore, such as VMFS, can succeed. If you later make additional snapshots and attempt to
migrate this VM back to vSphere Virtual Volumes storage, your attempt fails.
Cause
vSphere Virtual Volumes storage does not require that you use a particular hardware version for your
virtual machines. Typically, you can move a virtual machine with any hardware version to vSphere Virtual
Volumes storage. However, if you have a VM with memory snapshots, and plan to migrate this VM
between a virtual datastore and a nonvirtual datastore, use the VM of hardware version 11.
Non-VVols virtual machines of hardware version 11 or later use separate files to store their memory
snapshots. This usage is consistent with VMs on vSphere Virtual Volumes storage, where memory
snapshots are created as separate VVols instead of being stored as part of a .vmsn file in the VM home
directory. In contrast, non-VVols VMs with hardware version 10 continue to store their memory snapshots
as part of the .vmsn file in the VM home directory. As a result, you might experience problems or failures
when attempting to migrate these VMs between virtual and nonvirtual datastores.
Solution
To avoid problems when migrating VMs with memory snapshots across virtual and nonvirtual datastores,
use hardware version 11. Follow these guidelines when migrating version 10 or earlier VMs with memory
snapshots:
n
Migrating a version 10 or earlier VM with memory snapshots to a virtual datastore is not supported.
The only workaround is to remove all snapshots. Upgrading the hardware version does not solve this
problem.
n
Migrating a version 10 or earlier VM with memory snapshots from a virtual datastore to a nonvirtual
datastore, such as VMFS, can succeed. However, the migration might put the VM in an inconsistent
state. The snapshots that were taken on the virtual datastore use the vmem object. Any memory
snapshots taken after migrating to VMFS are stored in the .vmsn file. If you later attempt to migrate
this VM back to vSphere Virtual Volumes storage, your attempt fails. As with the previous case,
remove all snapshots to work around this problem.
vSphere Troubleshooting
VMware, Inc. 79