Migration with VMotion Causes the Creation of Incremented Files when Migration of a VirtualCenter 1.0.x Virtual Machine Fails (1386)
This renaming of old virtual machine files has a side effect if the migration fails. Even on a failed migration, VirtualCenter retains the knowledge that a particular name was used, and it does not reuse that name for future migrations. So, if you attempt to migrate a virtual machine using the old naming structure, to, for example, /home/vmware/vmtest on the destination host, and that migration fails, then the next attempt to migrate the machine tries to use the name /home/vmware/vmtest_1. If that migration also fails, then the next attempt tries the name /home/vmware/vmtest_2, and so forth.
Once a migration succeeds, then this iterative naming stops, as the old virtual machine files have been successfully moved into the new naming structure.