Running Linux, 5th Edition - Matthias Kalle Dalheimer [49]
First of all, be sure you actually installed LILO or GRUB when installing the Linux software. If not, the system will still boot Windows (or whatever other operating system you may have) when you attempt to boot from the hard drive. In order to boot Linux from the hard drive, you need to install LILO or GRUB (see the section "Using GRUB" in Chapter 17).
On the other hand, if you did install LILO, and another operating system boots instead of Linux, you have LILO configured to boot that other operating system by default. While the system is booting, hold down the Shift or Ctrl key and press Tab at the boot prompt. This should present you with a list of possible operating systems to boot; select the appropriate option (usually just linux) to boot Linux.
If you wish to select Linux as the default operating system to boot, you will need to reinstall LILO.
It also may be possible that you attempted to install LILO, but the installation procedure failed in some way. See the previous item on installation.
Problems logging in
After booting Linux, you should be presented with a login prompt:
Linux login:
At this point, either the distribution's documentation or the system itself will tell you what to do. For many distributions, you simply log in as root, with no password. Other possible usernames to try are guest or test.
Most Linux distributions ask you for an initial root password. Hopefully, you have remembered what you typed in during installation; you will need it again now. If your distribution does not ask you for a root password during installation, you can try using an empty password.
If you simply can't log in, consult your distribution's documentation; the username and password to use may be buried in there somewhere. The username and password may have been given to you during the installation procedure, or they may be printed on the login banner. Another option is to log into Linux in single-user mode by typing linux simple at the boot prompt.
One possible cause of this password impasse may be a problem with installing the Linux login and initialization files. If this is the case, you may need to reinstall (at least parts of) the Linux software, or boot your installation medium and attempt to fix the problem by hand.
Problems using the system
If login is successful, you should either be presented with a shell prompt (such as # or $) or be directly taken to a graphical desktop environment such as KDE or Gnome, and can happily roam around your system. The next step in this case is to try the procedures in Chapter 4. However, some initial problems with using the system sometimes creep up.
The most common initial configuration problem is incorrect file or directory permissions. This can cause the error message:
Shell-init: permission denied
to be printed after logging in. (In fact, anytime you see the message permission denied, you can be fairly certain it is a problem with file permissions.)
In many cases, it's a simple matter of using the chmod command to fix the permissions of the appropriate files or directories. For example, some distributions of Linux once used the incorrect file mode 0644 for the root directory (/). The fix was to issue the command:
# chmod 755 /
as root. (File permissions are covered in the section "File Ownership and Permissions" in Chapter 11.) However, in order to issue this command, you need to have booted from the installation medium and mounted your Linux root filesystem by hand—a hairy task for most newcomers.
As you use the system, you may run into places where file and directory permissions are incorrect or software does not work as configured. Welcome to the world of Linux! Although most distributions are quite trouble-free, you can't expect them to be perfect. We don't want to cover all those problems here. Instead, throughout the book we help you to solve many of these configuration problems by teaching you how to find them and fix them yourself. In Chapter 1, we discussed this philosophy in some detail. In Part