美国宇航局说，对飞行控制系统：“这三个数字式飞行控制计算机每有一个模拟备份。”

Says NASA about the flight control system: "Each of the three digital flight control computers had an analog backup."

youdao

硬链接的创建和维护开销很低，所以只使用增量方案就可以模拟完整备份的效果。

Hard links are very cheap to create and maintain, so a full backup is simulated using only an incremental scheme.

youdao

在实际提交备份之前，允许进行“模拟”(演习)。

Allowing a "simulation" (dry run) before actually committing to the backup.

youdao