• The first case concerns the root partition. When it is not mounted correctly, the boot process will halt and you will have to reboot the computer to try again.
• The easiest case is for encrypted volumes holding data like/homeor/srv. You can simply mount them manually after the boot.
However for dm-crypt this is a bit tricky. First you need to register the volumes with device mapper by running:
# /etc/init.d/cryptdisks start
This will scan all volumes mentioned in/etc/crypttaband will create appropriate devices un-der the/devdirectory after entering the correct passphrases. (Already registered volumes will be skipped, so you can repeat this command several times without worrying.) After successful regis-tration you can simply mount the volumes the usual way:
# mount /mount_point
• If any volume holding noncritical system files could not be mounted (/usror /var), the sys-tem should still boot and you should be able to mount the volumes manually like in the previous case. However, you will also need to (re)start any services usually running in your default runlevel because it is very likely that they were not started. The easiest way is to just reboot the computer.
7.3. Log In
Once your system boots, you’ll be presented with the login prompt. Log in using the personal login and password you selected during the installation process. Your system is now ready for use.
If you are a new user, you may want to explore the documentation which is already installed on your system as you start to use it. There are currently several documentation systems, work is proceeding on integrating the different types of documentation. Here are a few starting points.
Documentation accompanying programs you have installed can be found in/usr/share/doc/, un-der a subdirectory named after the program (or, more precise, the Ubuntu package that contains the program). However, more extensive documentation is often packaged separately in special documen-tation packages that are mostly not installed by default. For example, documendocumen-tation about the pack-age manpack-agement toolaptcan be found in the packagesapt-docorapt-howto.
In addition, there are some special folders within the/usr/share/doc/hierarchy. Linux HOWTOs are installed in .gz (compressed) format, in /usr/share/doc/HOWTO/en-txt/. After installing dhelp, you will find a browsable index of documentation in/usr/share/doc/HTML/index.html. One easy way to view these documents using a text based browser is to enter the following commands:
$ cd /usr/share/doc/
$ w3m .
The dot after thew3mcommand tells it to show the contents of the current directory.
You can also typeinfo commandorman commandto see documentation on most commands available at the command prompt. Typinghelpwill display help on shell commands. And typing a command
Chapter 7. Booting Into Your New Ubuntu System results scroll past the top of the screen, type| moreafter the command to cause the results to pause before scrolling past the top of the screen. To see a list of all commands available which begin with a certain letter, type the letter and then two tabs.
Chapter 8. Next Steps and Where to Go From Here
8.1. Shutting down the system
To shut down a running Ubuntu system, you must not reboot with the reset switch on the front or back of your computer, or just turn off the computer. Ubuntu should be shut down in a controlled manner, otherwise files might get lost and/or disk damage might occur.
Alternatively you can press the key combinationCtrl-Alt-Del. If the key combinations do not work, a last option is to log in as root and type the necessary commands. Userebootto reboot the system.
Use haltto halt the system without powering it off 1. To power off the machine, usepoweroff or shutdown -h now. The systemd init system provides additional commands that perform the same functions; for examplesystemctl rebootorsystemctl poweroff.
8.2. If You Are New to Unix
If you are new to Unix, you probably should go out and buy some books and do some reading. A lot of valuable information can also be found in the Debian Reference (http://www.debian.org/doc/user-manuals#quick-reference). This list of Unix FAQs (http://www.faqs.org/faqs/unix-faq/) contains a number of UseNet documents which provide a nice historical reference.
Linux is an implementation of Unix. The Linux Documentation Project (LDP) (http://www.tldp.org/) collects a number of HOWTOs and online books relating to Linux. Most of these documents can be in-stalled locally; just install thedoc-linux-htmlpackage (HTML versions) or thedoc-linux-text package (ASCII versions), then look in/usr/share/doc/HOWTO. International versions of the LDP HOWTOs are also available as Ubuntu packages.
8.3. Orienting Yourself to Ubuntu
Ubuntu is a little different from other distributions. Even if you’re familiar with Linux in other distri-butions, there are things you should know about Ubuntu to help you to keep your system in a good, clean state. This chapter contains material to help you get oriented; it is not intended to be a tutorial for how to use Ubuntu, but just a very brief glimpse of the system for the very rushed.
8.3.1. Ubuntu Packaging System
The most important concept to grasp is the Ubuntu packaging system, which may be familiar to those who have already used Debian. In essence, large parts of your system should be considered under the control of the packaging system. These include:
• /usr(excluding/usr/local)
• /var(you could make/var/localand be safe in there)
1. Under the SysV init systemhalthad the same effect aspoweroff, but with systemd as init system (the default in jessie)