有两种组织冗余处理机的方法：主动复制（active replication）和主机后备(primary backup)。考虑一个服务器的情况，当使用主动复制时，所有的处理机在所有的时间内都是作 为服务器（并行）使用，以彻底容错。
基于12个网页-相关网页
主备份(primary backup)：一个处理机作为服务器，只有当它失效后，才用另一个备份处理机去代替它。
Data from the LHC experiments is distributed around the globe, with a primary backup recorded on tape at CERN.
LHC实验产生的数据将分布到全世界，同时在CERN用磁带保有一份主备份。
youdao
There are even rumblings from many IT executives that the cloud backup is quicker than the primary backup.
FORBES: Why a Hybrid Approach to Cloud Computing Works Best for Now
There are cases in which cloud could function as the primary backup site, with on-premises backup as the failover environment.
That included making sure the Hackensack branch could serve as a backup home base in the event that both the primary and backup power at the main office went down.
FORBES: NJ Bank CEO: We're Running On The Backups To Our Backups
应用推荐
模块上移
模块下移
不移动