An administrator attempts to storage vMotion a VM or a VMDK residing on a vSAN datastore to another vSAN datastore or an external storage and vice-versa, encounters an error:
File [vsan-1] 321f3063-xxxx-xxxx-xxxx-xxxxxxxxxxxx/filename.vmdk is larger than the maximum size supported by datastore 'vsan-2'
vSAN 7.0.x
vSAN 8.0.x
This is due to Storage vMotion calculating the destination space required for the migration based on the storage policy in use at the source and destination datastore.
This issue is described in article vSAN svMotion caveats/considerations, please refer to the cause and resolution section to remediate the issue.