官方技术支持答复如下
Will free instances be deleted for paid accounts?
--Yes, that is true. Always Free compute instances will be reclaimed by Oracle, if the instance is in idle state during a 7 day period.
Reclamation of Idle Compute Instances
''Idle Always Free compute instances may be reclaimed by Oracle. Oracle will deem virtual machine and bare metal compute instances as idle if, during a 7-day period, the following are true:
CPU utilization for the 95th percentile is less than 10%
Network utilization is less than 10%
Memory utilization is less than 10% (applies to A1 shapes only)''
