vm.create() returns the new VM id.

src/api/vm.coffee

@@ -41,7 +41,7 @@ create = $coroutine ({
     vifs: VIFs
   })
 
-  return vm.id
+  return vm.$id
 
 create.permission = 'admin'
 

src/xapi.js

@@ -471,6 +471,9 @@ export default class Xapi extends XapiBase {
       await this.call('VM.set_VCPUs_at_startup')
     }
 
+    // Removes any preexisting entry.
+    await this.call('VM.remove_from_other_config', vm.$ref, 'disks').catch(noop)
+
     // TODO: remove existing VDIs (to make sure there are only those
     // wanted).
     //
@@ -487,9 +490,6 @@ export default class Xapi extends XapiBase {
         }
       })
 
-      // Removes any preexisting entry.
-      await this.call('VM.remove_from_other_config', vm.$ref, 'disks').catch(noop)
-
       await this.call('VM.add_to_other_config', vm.$ref, 'disks', vdisXml)
     }