Sometimes, it is preferred to make a copy of the VMDKs available at the remote site instead of performing the initial sync (or initial seed) of the target disk over the WAN connection. An example of this would be putting preseed VMDKs onto an external hard drive, shipping the hard drive to the target DR site, and then using these disks for preseeding, as described in Preseeding Volumes. This KB article describes how to obtain a copy of the source VMDKs so that they may be used for preseeding.
To copy VMDKs of running VMs, follow these steps:
- (Optional) Attach the external media to a host or hosts.
- Clone the source VMs - the clones should be cloned directly to the external media datastore or to a datastore where the vSphere client can later download the preseed disks.
- Once the clone is complete, right click on the VM and remove each disk from the clone. Note: Be sure to only remove the disks from the VM and not from the datastore!
- Remove the cloned VMs from inventory. The virtual disks (VMDKs) for each VM will remain in the cloned VM directory on the specified datastore.
- NOTE: Only the virtual disks need to be moved to the specified datastore. If the folder containing the disks is moved, vCenter's default behavior is to inflate thin provisioned disks within the directory which may not be desirable. By moving only the VMDKs, the existing provisioning method for the disk will be preserved.
- If the external media is attached to the hosts, detach the datastore and media. If the external media is not attached to the host, copy or download the VMDKs from the datastore to the external media.
- If the external media will not be the target datastore location, then move each individual VMDK from the external media to the correct target datastore at the target recovery site.
- Use these disks as the preseeded volumes.
More details on moving or copying a virtual disk in VMWare vSphere are available in the following VMware Knowledge Base Article - Moving or Copying Virtual Disks in a VMware Environment.