We have an ESXi server standing somewhere else. I can connect to the server with the vSphere client.
There is an external USB hard drive plugged into the server.
How can I copy a stopped VM to the external hard drive?
As ewwhite says in his comment, this is harder than it should be and is nigh-on impossible without doing a lot of advanced configuration.
This is mainly due to the fact that the underlying operating system behind vSphere (I believe it's loosely based on Red Hat Linux, but don't hold me to that!) was never designed to be a fully-featured OS - that's why it's defined as a hypervisor.
One option would be to get your hands dirty and poke around the ESXi console. You'd need to detect (try
Failing that, you can use USB passthrough to assign the attached USB device to a Windows VM, then use the vSphere Client from within that VM to save the directory to the USB device via the Datastore Browser.
This is possible in a round about way but requires a 2nd VM (or server).
Using the vmxnet network driver in the 2nd VM this will max out most drives. Requires an NFS server but is much faster than using the vsphere client download option and allows you to keep thin provisioned files.
Here is another method that gets the job done but not by connecting the USB drive to the VMhost. I use this when access to the ESXi host is not convenient.
1.From vSphere click on the VM and then the summary tab.
2.Right click on the datastore found under storage and then browse datastore.
3.Right click the directory with the VM and then download. (Note this can take a long time depending on how large and other obvious variables.)
4.Once you have the directory on your desktop you can do what ever is needed.