backup

There is no emergency back-up immediately available..没有立即就能获得的后备。

backup and recovery,备份与恢复

backup and restore,备份与还原

backup system,备用系统；后备系统

backup roll,支承辊；背辊；压辊

backup copy,副本；备份件

backup file,备份文件

backup software,文件备份

backup device,备份设备；备用设备

full backup,全部备份

system backup,系统备份；系统后备

backup storage,n. 后备存储器

file backup,文件备份；档案备份