A VirtualBox machine with the name already exists.

Error

[master] Matching MAC address for NAT networking...
A VirtualBox machine with the name 'vm-cluster-node1' already exists.
Please use another name or delete the machine with the existing
name, and try again.


Solution

Check all registered VMs

jagat@nanak-P570WM:~/development/tools/vagrant/mesos$ vboxmanage list vms
"Learning Puppet VM (pe-3.0.1)" {b73ed355-b5a3-4587-b983-008c2c0d4fdb}
"vm-cluster-node1" {d94d4187-c827-499a-9588-2591bd0d996b}
"precise64" {ab66affc-f92b-4a4c-88e2-7bac4db4f3e2}
jagat@nanak-P570WM:~/development/tools/vagrant/mesos$

Delete the VMs which is giving error

VBoxManage unregistervm vm-cluster-node1 --delete
VBoxManage unregistervm precise64 --delete

Done