Many of the topics covered in this short session will be discussed in more detail in the Monday evening FreeBSD session.

Why Did we Choose FreeBSD Rather than Linux?

• Very stable, especially under load.
• Superior TCP/IP stack (so much so that Microsoft literally stole it for use in Windows 2000).
• A merged virtual memory and filesystem buffer cache. Linux has three virtual memory systems in the 2.4 kernel track, and none of them perform as well.
• Heavily used and tested in large service providers.
• Scalability features as standard: e.g. pwd.db (indexed password database), which give you much better performance and scales well for very large sites. Linux uses a flat structure password file (/etc/passwd, /etc/shadow) that is inefficient for large sites.
• Optional "softupdates" filesystem combines crash-safety of BSD filesystem with speed of Linux filesystem - see /usr/src/sys/contrib/softupdates/README
• Similarities to BSDI and other "industrial strength" Unixes.
• see http://www.freebsd.org/features.html for more discussion.

Accounts Information

ACCOUNT:         root
PASSWORD:      Given in class

PLEASE! Do not change the root password. This will cause numerous problems throughout the workshop. The machine in front of you is yours for the duration of the workshop.

IF YOU CHANGE THIS PASSWORD YOUR MACHINE MAY BE REINSTALLED FROM SCRATCH!

Creating a User Account for Yourself

There are several ways to do this. We'll use one method for now, but you can use the interactive adduser script if you wish. This may require additional setup on your part the first time you run the script.

Below create the exim user account and your own personal user account as well using the following commands:

• pw useradd exim -u 90
• pw useradd username -m -G exim,wheel -s /usr/local/bin/bash

By placing your user in the wheel group this allows you to become the superuser root by using the su command. For more information on the pw command type man pw at the prompt.

Now you need to set the password for your new account so that you can login on that account. To do this type:

• passwd username

Some Basic FreeBSD Commands

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Command Line Editing

# bash
bash-2.03# 

If you change the default shell for root it is possible to create a situation where you cannot get a a shell if your machine's environment becomes damaged.

Using 'vi' as an Editor

vi <filename> .... [ESC]	-- edit a file
i .... [ESC]	-- insert text before cursor position
A .... [ESC]	-- append text to end of current line
x	-- delete character under cursor
dd	-- delete whole line
:wq .... [ESC]	-- save and exit
:q!	-- exit without saving
ESC Shift-ZZ	-- save and exit
o .... [ESC]	-- insert a line after cursor position
dd	-- delete the current line
h j k l	-- left|down|up|right (preferred)

Post-installation Configuration

However, you may find that some of this is quicker to do from the command line, some of which is explained below.

Short Example Using Some FreeBSD Commands

We will be placing source for programs during the workshop in a directory called /usr/local/src. See the Installation Notes section below for more information on partition slices.

To create /usr/local/src do the following:

• cd /usr/local
• mkdir src

Take a look at what's in /usr/local/src (which is nothing):

• ls
• ls -al (long listing and all files - note "." files)

SSH and SCP instead of Telnet and FTP

Note: if you are accustomed to using telnet, ssh looks almost identical and will behave the same for much of what you wish to do, but ssh has much more functionality available if you decide to use it.

Basic SSH and SCP Commands

ssh username@host	-- Connect to host using an encrypted session
scp filename user@host:/path/filename	-- Copy filename to path at host using username for authentication
scp -r * user@host:/path/.	-- Copy all files and all subdirectories to host under path specified. This is much more difficult using ftp.
scp user@host:/path/filename \ /path/filename	-- Copy file from host authenticating with user and put it in path with filename.
scp userX@hostX:/path/filename \ userY@hostY:/path/filename	-- Copy filename from hostX authenticating as userX to hostY authenticating as userY. This is something that you cannot do with ftp.

Getting FreeBSD 5.2 Files and Others

• ftp noc.ws.afnog.org
• login as userid anonymous
• username@ws.afnog.org
• cd pub/FreeBSD [to get FreeBSD 5.2 CD-ROM files]

pkg_add: Adding Packages or Ports by Hand

Many third-party software is supplied in ready-to-use form, but is not in the base system. This is (a) to keep the base system smaller, and (b) because of different licensing terms. (The FreeBSD license is actually less restrictive than the GNU/GPL license under which a lot of open-source software is distributed)

All this third-party software installs under /usr/local.

You can use /stand/sysinstall to add packages, but it is quicker to use 'pkg_add' from the command line. The example below assumes that you have the FreeBSD mounted to the mount point /cdrom. For example, to add the editor 'joe':

# cd /cdrom/packages/All
# ls
# pkg_add joe-2.8_5.tbz

[For the workshop you can simply enter in the command below. Note that you must be root
to do this.]

# pkg_add ftp://noc.ws.afnog.org/pub/FreeBSD/packages/All/joe-2.8_5.tbz

You can also compile packages directly from the source code, if you have the "ports" distribution installed. The ports system automatically fetches the source file via FTP or anonCVS, applies any FreeBSD-specific patches, and compiles and installs the code. A "package" is really just a "port" which has been compiled.

# cd /usr/ports/shells/bash
# make
# make install
# make clean

You can query installed packages, or package .tbz files, using pkg_info.

pkg_info -aI	-- list all installed packages (one line per package)
pkg_info joe-2.8_5	-- description of package
pkg_info -L joe-2.8_5	-- list all files in package
man pkg_info	-- read this for more details

Network Information

ifconfig

This is the command you use to interactively start and stop network interfaces and to define how they run. You need root access to use this command.

rc.conf

defaultrouter="80.248.72.126"
hostname="host1.t1.ws.afnog.org"
ifconfig_ed0="inet 80.248.72.1 netmask 255.255.255.248"

# On hosts where you don't want sendmail to accept incoming port 25
# (but you still want daemons to be able to send outgoing mail):
sendmail_flags="-q30m"

The sendmail flag is not set in this workshop. The full list of options, and their default values, can be found in /etc/defaults/rc.conf - but don't edit this file, edit /etc/rc.conf instead. This makes it easier to upgrade your system to a later version of FreeBSD.

Stopping and Starting the Network

You may be used to something like "/etc/rc.d/init.d/network stop" under Linux. Under FreeBSD this functionality resides in /etc/rc.conf and is parsed at system startup. So, to stop your currently running network first use ifconfig to figure out what interface you wish to stop.

• ifconfig

This displays your network interface status. Notice that "sis0" (Fast Ethernet) has an IP address assigned. Not that lo0 as an address as well. This is your loopback device. To bring sis0 down type:

• ifconfig sis0 down

Now to bring it back up just type:

• ifconfig sis0 up

There is quite a bit more to ifconfig and we'll discuss this during the Monday evening FreeBSD session as well, or you can type "man ifconfig" for more information. Review the "rc.conf" section above as well.

Stopping and Starting Services

By default, system services are configured in /etc/rc.conf and are started at system startup. If you need to start and stop one of these services (perhaps you changed the service's configuration file) you should do the following:

• ps -awx

or to find a particular running service, like sendmail, try:

• ps -awx | grep ssh

You'll get output that includes the process ID number on the left. If you make a change to the process's configuration, or just need to restart the process, you can do the following:

• kill -HUP process#

Note, if the service is a third party package, then you can often find configuration files for the service in /usr/local/etc/. In addition you may find shell scripts that can start and stop the service with command line parameters in /usr/local/etc/rc.d. Use these scripts instead, when available, to start and stop a service. Default services are now being placed in /etc/rc.d, so you may need to use one of these scripts to stop/start a service.

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Installation Notes

Slices and Partitions

The FreeBSD slice is then divided into "partitions". Example:

/dev/ad0     -- first ATA/ATAPI (IDE) hard drive
/dev/ad0s1   -- first slice (MSDOS "partition") on first IDE hard drive
/dev/ad0s1a  -- first partition in this FreeBSD slice
/dev/ad0s1b  -- second partition in this FreeBSD slice
/dev/ad0s1e  -- third (usable) partition

a:       root filesystem (/)
b:       swap space
e,f...:  other filesystems

Distribution sets

• "distribution sets" are the parts of the base system. The "bin" distribution is the minimum you can install. However there are additional distributions such as "manpages" and "XF86336".
• "ports" and "packages" are third-party software, not really part of FreeBSD itself, but supplied alongside it. "ports" build from source code, whilst "packages" are ports which have already been compiled and are ready to install.

Quick Installation Guide (Using CD-ROM & Sysinstall script)

Insert boot floppy, change to root floppy when prompted
Skip kernel config
Express install
Delete any existing partitions, then select "Entire disk"
Say Yes to standard partition entry
Select BootMgr

Create partition; ctrl-U to delete number presented, enter "100m" instead
  FS   /
Create partition; ctrl-U; 100m
  Swap
Create partition; ctrl-U; 400m
  FS   /var
Create partition; ctrl-U; 400m
  FS   /usr
Create partition; hit enter to accept number given (i.e. rest of disk)
  FS   /u

X-User  (must hit SPACEBAR, not Enter, to select it)
Yes install ports collection

Default answers to remaining questions (i.e. just hit Enter)
WAIT for install to complete
No extra options after install
Exit install
Reboot (remember to remove floppy and CD)
Login as root
halt

Label machine as being successfully installed.

The FreeBSD Directory Structure

The FreeBSD directory hierarchy is fundamental to obtaining an overall understanding of the system. The most important concept to grasp is that of the root directory, ``/''. This directory is the first one mounted at boot time and it contains the base system necessary to prepare the operating system for multi-user operation. The root directory also contains mount points for every other file system that you may want to mount.

A mount point is a directory where additional file systems can be grafted onto the root file system. Standard mount points include /usr, /var, /mnt, and /cdrom. These directories are usually referenced to entries in the file /etc/fstab. /etc/fstab is a table of various file systems and mount points for reference by the system. Most of the file systems in /etc/fstab are mounted automatically at boot time from the script rc(8) unless they contain the noauto option. Consult the fstab(5) manual page for more information on the format of the /etc/fstab file and the options it contains.

A complete description of the filesystem hierarchy is available in hier(7). For now, a brief overview of the most common directories will suffice.

A Few differences from Linux

Linux:   eth0 = first ethernet device (of any type)
FreeBSD: sis0 = first SIS900 10/100 ethernet, ed0  = first NE2000 device, ep0 = first 3Com 3c509, etc.

Linux:   COM1 serial port = /dev/ttyS0
FreeBSD: COM1 serial port = /dev/cuaa0 (call out) or /dev/ttyd0 (call in)

Linux:   /etc/inittab configures incoming serial connections
FreeBSD: /etc/ttys configures incoming serial connections

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