新接触ubuntu（base on debian）的人，大多会因为安装中没有提示root密码而不太清楚为什么会这样。
如何设定/改变/启用 root 使用者的密码?
sudo passwd root
为了启用 root 帐号 (也就是 设置一个口令) 使用:
sudo passwd root
当你使用完毕后屏蔽 root 帐号 使用:
sudo passwd -l root
这个将锁住 root 帐号.
如何在终端机模式下切换到 root 身份?
sudo -s -H



如何安装Vm tools

Mware Tools for Linux Guests

Power on the virtual machine.
After the guest operating system has started, prepare your virtual machine to install

VMware Tools.
Choose File > Install VMware Tools.

The remaining steps take place inside the virtual machine.

Be sure the guest operating system is running in text mode. You cannot install VMware Tools

while X is running.
As root (su -), mount the VMware Tools virtual CD-ROM image, change to a working directory

(for example, /tmp), uncompress the installer, then unmount the CD-ROM image.
Note: You do not use an actual CD-ROM to install VMware Tools, nor do you need to download

the CD-ROM image or burn a physical CD-ROM of this image file. The VMware Workstation

software contains an ISO image that looks like a CD-ROM to your guest operating system.

This image contains all the files needed to install VMware Tools in your guest operating

system.

Note: Some Linux distributions use different device names or organize the /dev directory

differently. If your CD-ROM drive is not /dev/cdrom, modify the following commands to

reflect the conventions used by your distribution.

mount /dev/cdrom /mnt
cd /tmp
tar zxf /mnt/vmware-linux-tools.tar.gz
umount /mnt

Run the VMware Tools installer.
cd vmware-tools-distrib
./vmware-install.pl

Log out of the root account.
exit

Start X and your graphical environment.
In an X terminal, launch the VMware Tools background application.
vmware-toolbox &

Note: You may run VMware Tools as root or as a normal user. To shrink virtual disks, you

must run VMware Tools as root (su -).

Starting VMware Tools Automatically

You may find it helpful to configure your guest operating system so VMware Tools starts

when you start your X server. The steps for doing so vary depending on your Linux

distribution and your desktop environment. Check your operating system documentation for

the appropriate steps to take.

For example, in a Red Hat Linux 7.1 guest using GNOME, follow these steps.

Open the Startup Programs panel in the GNOME Control Center.
Main Menu (click the foot icon in the lower left corner of the screen) > Programs >

Settings > Session > Startup Programs

Click Add.
In the Startup Command field, enter vmware-toolbox.
Click OK, click OK again, then close the GNOME Control Center.
The next time you start X, VMware Tools starts automatically.

Uninstalling VMware Tools

If you need to remove VMware Tools from your Linux guest operating system, log on as root

(su -) and run the following command:

vmware-uninstall-tools.pl

VMware Tools for FreeBSD Guests

Power on the virtual machine.
Prepare your virtual machine to install VMware Tools.
Choose File > Install VMware Tools.

The remaining steps take place inside the virtual machine, not on the host computer.

Be sure the guest operating system is running in text mode. You cannot install VMware Tools

while X is running.
As root (su -), mount the VMware Tools virtual CD-ROM image, change to a working directory

(for example, /tmp), uncompress the installer, then unmount the CD-ROM image.
Note: You do not use an actual CD-ROM to install VMware Tools, nor do you need to download

the CD-ROM image or burn a physical CD-ROM of this image file. The VMware Workstation

software contains an ISO image that looks like a CD-ROM to your guest operating system.

This image contains all the files needed to install VMware Tools in your guest operating

system.

mount /cdrom
cd /tmp
tar zxf /cdrom/vmware-freebsd-tools.tar.gz
umount /cdrom

Run the VMware Tools installer.
cd vmware-tools-distrib
./vmware-install.pl

Log out of the root account.
exit

Start X and your graphical environment
In an X terminal, launch the VMware Tools background application.
vmware-toolbox &

Note: You may run VMware Tools as root or as a normal user. To shrink virtual disks, you

must run VMware Tools as root (su -).

Note: In a FreeBSD 4.5 guest operating system, sometimes VMware Tools does not start after

you install VMware Tools, reboot the guest operating system or start VMware Tools on the

command line in the guest. An error message appears:

Shared object 'libc.so.3' not found.

The required library was not installed. This does not happen with full installations of

FreeBSD 4.5, but does occur for minimal installations. To fix the problem of the missing

library, take the following steps:

Insert and mount the FreeBSD 4.5 installation CD or access the ISO image file.
Change directories and run the installation script.
cd /cdrom/compat3x
./install.sh

果然按着上面的步骤我的Vm上面的ubuntu安装成功了，怎么和windows这么的类似啊，终于理解
windows是名牌西服，而Linux是定制西服的道理了。
 我最近想学习一下嵌入式Linux，了解操作系统的原理，所以就弄一个Linux的环境玩玩