Instance may be destroyed by mistake once nova compute configuring in confilct

[H3C iMC]

After an instance evacuated from a failed host, the instance will be destroyed to avoid duplicated running when the failed host recovers and starts . This operation may be destroy an instance wrongly when configuring multi nova computes related to the same vcenter cluster by mistake. The cost is too heavy for the mistake. Nova should check whether the instance on the same host actual.