If you have multiple operating systems installed on your server, you need to select which one you want from the boot loader menu.

如果服务器中安装了多个操作系统，您需要从引导加载程序菜单中选择需要引导的操作系统。

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Used in this way, another boot loader resides in the MBR, and GRUB's menu appears only when that boot loader chain-loads GRUB.

这种方式下，另一个引导加载程序驻留在MBR中，仅当引导加载程序链式加载grub时才出现GRUB菜单。

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When the GRUB menu is displayed, you select a boot image using the cursor movement keys to move up and down the list.

GRUB菜单显示时，可以使用光标移动键在列表中上下移动，选择一个引导映像。

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