High availability of your data is a must for the on-demand environment. 数据的高可用性对于随需应变的环境来说是必需的。
High availability began in the 1970s with mainframe systems,which support high up time as part of their inherent design. 利用大型机系统的高可用性始于二十世纪七十年代,这些系统作为它们固有设计的一部分,能保证系统长时间正常工作。