1.  如果只有 电脑上只安装了一个系统，则默认不会显示启动菜单。

2.  按住shift或者在某些情况下按住esc来显示启动菜单。

3.  没有了/boot/grub/menu.lst，该文件被/boot/grub/grub.cfg取代。

4.  There is no "/find boot/grub/stage1" at the grub prompt. Stage 1.5 has been eliminated。

5.  主要配置文件是/boot/grub/grub.cfg。

6.  grub.cfg文件被update-grub更新。

7.  可用的内核都会被自动添加到启动菜单，当执行update-grub命令时。

8. 当用户想要创建一个启动项时，可以编辑/etc/grub.d/40.custom文件。

9.  启动菜单显示配置的主要文件是/etc/default/grub。

10. 配置启动菜单的配置文件有很多，除了/etc/default/grub外，还有/etc/grub.d/目录中的文件。

11.分区（partition）的表示数字不是从0 开始了，而是从1开始了。设备号没有变，第一个设备还是用hd0表示，在/boot/grub/device.map(自己新建吧要)可以指定设备的表示名称。

12.当执行update-grub时，自动搜索其他的操作系统，如windows，搜索到的操作系统会自动添加到grub的启动菜单中。

13.改变配置文件之后，要执行update-grub才使新的配置生效。

原文：

RUB 2's default menu will look familiar to GRUB users but there are a great number of differences beneath the surface.

1.   On a new installation of Ubuntu 9.10 or later with no other installed operating systems, GRUB 2 will boot directly to the login prompt or Desktop. No menu will be displayed.

2.  Hold down SHIFT to display the menu during boot. In certain cases, pressing the ESC key may also display the menu.

3.   No /boot/grub/menu.lst. It has been replaced by /boot/grub/grub.cfg.

4.  There is no "/find boot/grub/stage1" at the grub prompt. Stage 1.5 has been eliminated.

5.   The main Grub 2 configuration file, normally located in the /boot/grub folder, is grub.cfg. It is the product of various scripts and should not normally be edited directly.

6.  grub.cfg is overwritten by certain Grub 2 package updates, whenever a kernel is added or removed, or when the user runs update-grub.

7.  The menu list of available Linux kernels is automatically generated by running update-grub.

8.  The user can create a custom file in which the user can place his own menu entries. This file will not be overwritten. By default, a custom file named 40_custom is available for use in the /etc/grub.d folder.

9.  The primary configuration file for changing menu display settings is called grub and by default is located in the /etc/default folder.

10. There are multiple files for configuring the menu - /etc/default/grub mentioned above, and all the files in the /etc/grub.d/ directory.

11. Partition numbering has changed. The first partition is now 1 rather than 0. The first device/drive is still hd0 by default (no change). These designations can be altered if necessary in the device.map file in the /boot/grub folder.

12. Automated searches for other operating systems, such as Windows, are accomplished whenever update-grub is executed. Operating systems found will be placed in the Grub 2 menu.

13.Changes made in the configuration files will not take effect until the update-grub command is executed.