With Storage vMotion, you can migrate a virtual machine and its disk files from one datastore to another while the virtual machine is running. You can also move virtual machines off of arrays for maintenance or to upgrade.

With Storage vMotion you also have the flexibility to optimize disks for performance, or to transform disk types, which you can use to reclaim space.

You can choose to place the virtual machine and all its disks in a single location, or you can select separate locations for the virtual machine configuration file and each virtual disk. The virtual machine does not change execution host during a migration with Storage vMotion.

During a migration with Storage vMotion, you can change the disk provisioning type.

Migration with Storage vMotion changes virtual machine files on the destination datastore to match the inventory name of the virtual machine. The migration renames all virtual disk, configuration, snapshot, and .nvram files. If the new names exceed the maximum filename length, the migration does not succeed.

Storage vMotion has several uses in administering virtual infrastructure, including the following examples of use.

  • Storage maintenance and reconfiguration. You can use Storage vMotion to move virtual machines off a storage device to allow maintenance or reconfiguration of the storage device without virtual machine downtime.
  • Redistributing storage load. You can use Storage vMotion to redistribute virtual machines or virtual disks to different storage volumes to balance capacity or improve performance.

Storage vMotion Requirements and Limitations

A virtual machine and its host must meet resource and configuration requirements for the virtual machine disks to be migrated with Storage vMotion.

Storage vMotion is subject to the following requirements and limitations:

  • Virtual machine disks must be in persistent mode or be raw device mappings (RDMs). For virtual compatibility mode RDMs, you can migrate the mapping file or convert to thick-provisioned or thin-provisioned disks during migration if the destination is not an NFS datastore. If you convert the mapping file, a new virtual disk is created and the contents of the mapped LUN are copied to this disk. For physical compatibility mode RDMs, you can migrate the mapping file only.
  • Migration of virtual machines during VMware Tools installation is not supported.
  • Because VMFS3 datastores do not support large capacity virtual disks, you cannot move virtual disks greater than 2 TB from a VMFS5 datastore to a VMFS3 datastore.
  • The host on which the virtual machine is running must have a license that includes Storage vMotion.
  • ESXi 4.0 and later hosts do not require vMotion configuration to perform migration with Storage vMotion.
  • The host on which the virtual machine is running must have access to both the source and target datastores.
  • For limits on the number of simultaneous migrations with vMotion and Storage vMotion, see vCenter Server Limits on Simultaneous Migrations.

How to Migrate Your Virtual Machine with Storage vMotion

Learn how to use Storage vMotion to migrate the configuration file of a virtual machine and its virtual disks to a new storage. You can migrate the virtual machine while it is powered on.

Prerequisites

  • Verify that your system satisfies the requirements for Storage vMotion. See Storage vMotion Requirements and Limitations.

  • For migration of a virtual machine with NVIDIA vGPU, verify that the ESXi host on which the virtual machine runs has a free vGPU slot when the host is with version 7.0 Update 2 and earlier. Starting with vSphere 7.0 Update 3, the source hosts are not required to have a free vGPU slot.
  • Verify that the vgpu.hotmigrate.enabled advanced setting is set to true. For more information about configuring vCenter Server advanced settings, see Configure Advanced Settings in the vCenter Server Configuration documentation.

  • Required privilege: Resource.Migrate powered on virtual machine

Procedure

  1. Right-click the virtual machine and select Migrate.
    1. To locate a virtual machine, select a data center, folder, cluster, resource pool, host, or vApp.
    2. Click the Virtual Machines tab.
  2. Click Change storage only and click Next.
  3. Select the format for the virtual machine's disks.
    Option Action
    Same format as source Use the same format as the source virtual machine.
    Thick Provision Lazy Zeroed Create a virtual disk in a default thick format. Space required for the virtual disk is allocated during creation. Any data remaining on the physical device is not erased during creation. Instead, it is zeroed out on demand on first write from the virtual machine.
    Thick Provision Eager Zeroed Create a thick disk that supports clustering features such as Fault Tolerance. Space required for the virtual disk is allocated at creation time. In contrast to the thick provision lazy zeroed format, the data remaining on the physical device is zeroed out during creation. It might take longer to create disks in this format than to create other types of disks.
    Thin Provision Use the thin provisioned format. At first, a thin provisioned disk uses only as much datastore space as the disk initially needs. If the thin disk needs more space later, it can expand to the maximum capacity allocated to it.
  4. Select a virtual machine storage policy from the VM Storage Policy drop-down menu.

    Storage policies specify storage requirements for applications that run on the virtual machine. You can also select the default policy for vSAN or Virtual Volumes datastores.

    Important:

    If the virtual machine hard disks use different storage policies, the new policy that you select only applies to non-PMem hard disks. PMem hard disks are migrated to the host-local PMem datastore of the destination host.

  5. Select the datastore location where you want to store the virtual machine files.

    Option

    Action

    Store all virtual machine files in the same location on a datastore.

    Select a datastore and click Next.

    Store all virtual machine files in the same Storage DRS cluster.

    1. Select a Storage DRS cluster.

    2. (Optional)

      To deactivate Storage DRS with this virtual machine, select Disable Storage DRS for this virtual machine and select a datastore within the Storage DRS cluster.

    3. Click Next.

    Store virtual machine configuration files and disks in separate locations.

    1. Click Advanced.

      Note:

      You can use the Advanced option to downgrade from or upgrade to PMem storage.

    2. For the virtual machine configuration file and for each virtual disk, select Browse, and select a datastore or Storage DRS cluster.

      Note:

      Configuration files cannot be stored on a PMem datastore.

    3. (Optional)

      If you selected a Storage DRS cluster and do not want to use Storage DRS with this virtual machine, select Disable Storage DRS for this virtual machine and select a datastore within the Storage DRS cluster.

    4. Click Next.
  6. On the Ready to complete page, review the details and click Finish.

Results

vCenter Server moves the virtual machine to the new storage location. Names of migrated virtual machine files on the destination datastore match the inventory name of the virtual machine.

Event messages appear in the Events tab. The data displayed on the Summary tab shows the status and state throughout the migration. If errors occur during migration, the virtual machines revert to their original states and locations.