Practically it means when Begin backup is issued, an operating system copy should follow, and then quickly end by an End backup.

实际上，在执行 Begin backup后，接下来应该立刻执行系统复制，然后由 End backup 来快速结束操作。

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Online backup occurs either when any or all online table spaces are put into online backup mode by issuing a command Alter Tablespace ts_name Begin Backup.

通过执行命令“Alter Tablespace ts_name Begin Backup”，将任何或所有联机表空间置于联机备份模式来启动联机备份。

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Now simply click "Get mail" and let the Gmail backup begin.

现在简单地点击“接受邮件”然后让gmail备份开始。

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Second, nuclear reactors can only be run above maximum capacity for a short period before they begin experiencing complications, so each region maintains backup facilities to burn fuel oil or natural gas at peak periods or for when the nuclear reactors are offline.

FORBES: Japanese Oil Demand Likely To Jump

He played in 61 games in his first two seasons with the Devils, winning 32, but the starting position will belong to Brodeur until he quits, if ever, and when the Stanley Cup playoffs begin and if the Devils are in them, the backup finds the bench.

WSJ: Even the Devils' Backup Is a Wall