Chapter 3. Installation Walk-Through
Straightforward questions.
Will you take the default prompts?
Think before you choose.
Armed with your OpenBSD software and a computer with supported hardware, you are now ready to start an actual installation. This chapter takes you through a full installation on amd64 and i386 systems via CD and FTP, booting from a CD or floppy disk.
In this chapter, I assume that you’re dedicating your computer to OpenBSD. You can install multiple operating systems on a single computer, of course, but that’s a less common use case. If you want to install multiple operating systems on your computer, follow the instructions in the OpenBSD FAQ. (When installing multiple operating systems on a single computer, it’s easy to accidentally damage one of those operating systems, so proceed with caution.)
Before you begin OpenBSD installation, make sure the data on your machine is backed up! When you dedicate your machine to OpenBSD, you’ll overwrite the entire hard drive.
Hardware Setup
Before you begin, verify that OpenBSD supports your hardware. You’ll find the supported hardware list for the most recent version of OpenBSD on the platform-specific pages of the OpenBSD website (http://www.OpenBSD.org/i386.html for i386 and http://www.OpenBSD.org/amd64.html for amd64), listing hardware that has been verified to work by the OpenBSD team.
If you find that your hardware isn’t listed, it might still run OpenBSD. In fact, a lot of unsupported hardware will run OpenBSD perfectly, but not all hardware has been tested, simply because the OpenBSD team doesn’t have access to all hardware ever manufactured. If you’re worried about a particular device, search the mailing list archives to see if it’s supported.
The hardware compatibility lists frequently identify devices by chipset, not by vendor or model. The chipset is the actual hardware name, not the model name, which can cause a bit of confusion because, after all, when you buy a computer, the network card is frequently listed as a “gigabit Ethernet,” not as an “Intel PRO/1000MT Dual Port Server Adapter model PWLA8492MT.” To make matters worse, many vendors use identical hardware under a separate brand or model name or use different hardware under the same brand or model name. For example, Linksys sold many different network card models under the model name EtherLink. (Fortunately, this issue mostly applies to the lower end of the market, and OpenBSD almost always supports these older chipsets.)
Even if you’re not sure that you hardware is supported, you can still try installing OpenBSD to see what happens. The boot messages will offer a lot of information about the hardware you have.
BIOS Configuration
Be sure to evaluate your system’s Basic Input/Output System (BIOS) before installing OpenBSD. Because every BIOS differs, I can’t offer exact instructions on configuring yours. Your best bet is to consult your motherboard’s manual or the Internet.
Also, if your BIOS needs updating, take care of that before installing OpenBSD. Finally, check the boot device order, and be sure that it makes sense for how you plan to install your system.
With your hardware set up, get the boot media.
Making Boot Media
We’ll cover booting the OpenBSD installer from a CD or floppy disk. Generally, booting via CD is preferable because all amd64 systems can boot from CD, as can most functioning i386 systems. We’ll start by making floppies for installation on old i386 hardware and then move on to CDs. While installing from USB and into virtual systems is possible, neither is supported. We’ll cover both of those installation types later in the book, in Chapter 23.
Making Boot Floppies
You need to make boot floppies only if your hardware does not boot from CD, or if you have a floppy but not a CD drive. The OpenBSD boot floppies contain a very limited subset of OpenBSD—just enough to recognize your hardware, format your disk, and download and extract the file sets. In addition to the floppies themselves, you’ll also need a working Internet connection via Ethernet.[8] Because the full kernel is larger than a single floppy can hold, OpenBSD provides three floppy images for i386 hardware, each targeting a specific type of hardware. Each image name includes the release number. For example, the floppy images for release 5.3 are named floppy53.fs, floppyB53.fs, and floppyC53.fs. Download the image that most closely describes your system, as follows:
floppyXX.fs. This is the image for the most common i386 hardware. It will boot the average workstation or low-end server.
floppyBXX.fs. This image includes drivers for gigabit Ethernet cards, SCSI, and RAID. It’s meant for higher-end i386 servers.
floppyCXX.fs. This image supports PCMCIA and CardBus. It’s meant for laptops.
OpenBSD provides only one floppy image for amd64 hardware: floppyXX.fs. (The amd64 platform doesn’t carry around 20 years of legacy drivers as baggage, so everything fits on a single disk.) Be sure to use the floppy image found in the amd64 directory. The amd64 image uses the same name as the standard i386 floppy.
Once you have the appropriate image file, you must copy it onto a floppy disk. You cannot use basic filesystem-level copying, such as Windows drag-and-drop, because the image files include not only files but also a filesystem. You must use appropriate tools to copy the images to a floppy.
Creating Floppies on Unix-like Systems
If you’re already running a Unix-like system, create your floppy with dd(1). You’ll need to know your floppy drive’s device name, which is probably /dev/fd0, /dev/floppy, /dev/rfd0, or /dev/rsd0 (for USB floppy drives). Once you know the device name, tell dd to copy the image to that disk device with a command like this:
# dd if=filename of=full-path-to-floppy-device
For example, to create a disk from image floppyB52.fs with the floppy device name /dev/fd0c, enter the following:
# dd if=floppyB52.fs of=/dev/fd0cIf dd gives you an error immediately or exits silently without writing to the floppy disk, try specifying a different floppy disk device.
Creating Floppies on Microsoft Systems
If you need to create a floppy on a descendant of Windows NT (including all modern Windows desktop operating systems), you’ll need an image-writing program. In the tools directory of your OpenBSD release, you’ll find a program named ntrw.exe. This program copies disk images to a disk. Download the program, open a command prompt, navigate to the folder containing ntrw.exe, put your blank floppy in the drive, and run this command:
C:> ntrw floppyB53.fs a:If you get a permissions error, you might need to run your command prompt as Administrator. If the command still fails, chances are good that you’re using the bad floppy disk you tucked away in a drawer 15 years ago. Try another one.
Making Boot CDs
OpenBSD provides three ISO images for i386 and two for amd64, as follows:
cdXX.iso. This image contains the kernel and installer, but no file sets. It’s used to boot a system into the minimal state where the installer can run. Once the system has booted, it fetches the file sets over the network.
installXX.iso. This image contains everything in the cdXX.iso image, as well as the file sets. Use it to install this version of OpenBSD on multiple systems.
cdemuXX.iso. Some older i386 systems have a BIOS that makes CD drives emulate floppy drives. If you have a system like this, use cdemuXX.iso. If you’re unsure whether you need this image, you don’t. If you’ve ever owned one of these CD drives, you’ve probably replaced it by now. If you haven’t, maybe you should.
Note
Remember that you can save yourself the trouble of selecting an ISO by buying an official CD set, which will Just Work and will also contain precompiled packages.
The process of getting the ISO onto a physical disk varies widely from operating system to operating system. On a Microsoft Windows system, right-click the ISO and select Burn to Disc. Unix-like systems use several different programs, such as burncd and cdrecord. Different Linux versions have innumerable ISO-burning front ends integrated into their desktop environments. Check online for instructions on burning a CD on your particular operating system.
Installing OpenBSD
Once you boot from your chosen media, you should see something like this:
> OpenBSD/amd64 BOOT 3.18 boot>
If you need to interrupt the boot process for any reason, you can do so at this point. We’ll discuss how to interrupt the boot process in Chapter 5, and reasons for doing so throughout the book.
If you wait five seconds, OpenBSD should boot. The kernel will then introduce itself and begin identifying your hardware.
booting 1cd0a:/5.3/amd64/bsd.rd: 2986868+913996+2861496+0+504624 [89+318288+205653]=0xb6f578 entry point at 0x1001e0 [7205c766, 34000004, 24448b12, 1608a304] Copyright (c) 1982, 1986, 1989, 1991, 1993 The Regents of the University of California. All rights reserved. Copyright (c) 1995-2012 OpenBSD. All rights reserved. http://www.OpenBSD.org 2 OpenBSD 5.3 (RAMDISK_CD) #23: Sun Feb 12 09:45:07 MST 2012 deraadt@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/RAMDISK_CD real mem = 1072627712 (1022MB) avail mem = 1032290304 (984MB) …
In this output, you can tell at 1 from which device the system is booting—CD drive 0 in this case. Next, you see the copyright information, followed by the directory in which your kernel was compiled at 2. You can see that this is an OpenBSD snapshot kernel, compiled by user deraadt on host amd64.openbsd.org.
At this point, OpenBSD should probe your hardware and display the results as it attaches device drivers.
Running the Installation Program
Once the boot messages pass, you should see the following text:
Welcome to the OpenBSD/amd64 5.3 installation program.
(I)nstall, (U)pgrade or (S)hell? iAs you can see, there are three options: Install, Upgrade, and Shell. The OpenBSD installer is a shell script that calls programs to download files, format disks, and otherwise prepare your system. It might not be pretty, but it is extremely fast and, in educated hands, extremely powerful.
The Shell option will drop you into an OpenBSD command line, where you have access to the commands on the installation disk. These minimal commands might suffice to repair a damaged system. We’ll examine the Upgrade option in Chapter 20.
Enter i to choose Install. You should see a welcome message and a few basic instructions:
At any prompt except password prompts you can escape to a shell by typing '!'. Default answers are shown in []'s and are selected by pressing RETURN. You can exit this program at any time by pressing Control-C, but this can leave your system in an inconsistent state. 1 Terminal type? [vt220] 2 System hostname? (short form, e.g. 'foo') caddis
The installer shows default answers in square brackets. To use the default, just press ENTER.
If your system has a standard keyboard and monitor, OpenBSD will use it as the standard VT220 terminal, as shown at 1. If you have an unusual terminal connected to your system, you’re probably an old geezer who knows exactly what terminal type it is. If you’re a young kid using some ancient, unidentified, dust-covered terminal found in a disused laboratory at the back of an abandoned fireworks factory because you thought it would be nifty, stop now and get a standard monitor and keyboard. While OpenBSD probably supports that antediluvian console, this is not the time to try it.
Next, the installer should prompt you for the system’s short hostname at 2, which will be a single word to identify your system. This particular computer is named caddis; you can name yours whatever you like.
Now to configure the network:
1 Available network interfaces are: em0 em1 vlan0. 2 Which one do you wish to configure? (or 'done') [em0] 3 IPv4 address for em0? (or 'dhcp' or 'none') [dhcp] 192.0.2.85 4 Netmask? [255.255.255.0] 255.255.255.128 5 IPv6 address for em0? (or 'rtsol' or 'none') [none] Available network interfaces are: em0 em1 vlan0. 6 Which one do you wish to configure? (or 'done') [done] 7 Default IPv4 route? (IPv4 address, 'dhcp' or 'none') 192.0.2.1 add net default: gateway 192.0.2.1 8 DNS domain name? (e.g. 'bar.com') [my.domain] blackhelicopters.org 9 DNS nameservers? (IP address list or 'none') [none] 192.0.2.2 192.0.2.10
At 1, the installer lists the network interfaces it recognizes on your machine. It has found three: em0, em1, and vlan0. The first two, em0 and em1, are network cards. I chose em0 at 2, the installer’s default, by pressing ENTER. Avoid configuring a virtual local area network (VLAN) during installation if possible, especially on your first installation. If you need a VLAN to connect to the Internet, see Chapter 12.
When asked at 3 if you want to give a static IP address, you can choose to use DHCP by pressing ENTER. I chose to enter a static address because I’ll be using this machine as a server. (If you don’t need a static address, you can just let DHCP automatically assign you an IP address.)
When you use a static address, you must also enter a netmask at 4 and (if desired) an IPv6 address at 5. Now, having configured one network card, OpenBSD asks at 6 if you’ve finished configuring the network. If you wanted the installer to walk you through configuring the second network card, you would enter em1 instead of accepting the default of done.
If you assign a static IP address, you must also configure a static route if you want to access the Internet, as shown at 7. Similarly, you need to tell your host its domain name at 8 and the IP address of at least one name server at 9.
At this point, you should be on your local network. If you can’t access the network, you probably entered something incorrectly. If nothing else, you can use an exclamation point (!) to interrupt the installation and get a shell prompt. (Chapter 12 discusses OpenBSD’s network configuration in greater depth.)
Multiple Network Cards
Our example server has multiple network interfaces. I chose to configure interface em0 because that machine was in front of me, and if I chose the wrong network card, I could move the cable. But what if you don’t have physical access to your machine? If you had two different network cards (say, an Intel and a 3Com), you would have a better idea which card is which, but having two identical cards leaves you guessing which card has a cable plugged into which network.
Luckily, the OpenBSD installer lets you escape to a command prompt to do a little investigating. How is this useful here? Network interfaces that are plugged in will tell you what kind of connection they have, and disconnected or otherwise failed interfaces will report that they have no media. Here’s how you can interrupt the installer to identify the live interface:
Available network interfaces are: em0 em1 vlan0. 1 Which one do you wish to configure? (or 'done') [em0] ! Type 'exit' to return to install. 2 # ifconfig lo0: flags=8008<LOOPBACK,MULTICAST> mtu 33152 em0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500 lladdr 00:0c:29:aa:09:21 3 media: Ethernet autoselect (1000baseT full-duplex,master) status: unknown em1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500 lladdr 00:0c:29:aa:09:2b 4 media: Ethernet autoselect (none) status: unknown vlan0: flags=0<> mtu 1500 lladdr 00:00:00:00:00:00
Rather than choosing an interface, escape to a command prompt at 1 by entering an exclamation point (!). Then ask OpenBSD at 2 to tell you about its network interfaces by running ifconfig. You can see interfaces em0 and em1 in the output. While em0 reports at 3 that it’s running 1000baseT at full-duplex, at 4 you can see that em1 has a media type of none. Interface em0 is plugged in, so that’s the interface I want to configure. Enter exit to return to the installer, and proceed to configure card em0.
Setting Up Services and the First User
The installer should now ask you to configure some basic system parameters:
1 Password for root account? (will not echo) Password for root account? (again) 2 Start sshd(8) by default? [yes] 3 Start ntpd(8) by default? [no] yes NTP server? (hostname or 'default') [default] 4 Do you expect to run the X Window System? [yes] 5 Do you want the X Window System to be started by xdm(1)? [no] 6 Change the default console to com0? [no]
At 1, enter your root password twice. If the passwords don’t match, the installer will make you do it over until they do.
You can enable the Secure Shell (SSH) daemon at 2 so that you can remotely connect to this machine immediately after installation. If you enable SSH but do not create a user later in the installation, you can SSH to the machine as root. This is a Very Bad Idea when using password authentication and will let intruders more easily compromise your server. If you enable sshd here, be absolutely certain to create a user during the installation process! If you don’t, at least disable SSH logins by the root account immediately after installing OpenBSD, as discussed in Chapter 4.
Correct time is important on a network. I usually enable the Network Time Protocol (NTP) daemon ntpd(8) during the installation process, as shown at 3. OpenBSD chooses a set of publicly accessible time servers by default, but you can specify a local time server if you have one available.
Now tell the installer at 4 if you intend to run X Windows. X requires that software be permitted fairly broad access into the kernel. If the installer detects a graphic console, it defaults to permitting X. If you don’t need a graphic console, disable X access.
If you’re running X, you might also want the X display manager xdm(1). At 5, tell the installer if you want xdm. By default, OpenBSD doesn’t start xdm when it boots; you’re generally better off installing OpenBSD on your system than configuring X, so I’ve accepted the default of no here.
If you want this system to use a serial port as the console, you can set that during the installation at 6. I discuss serial consoles in Chapter 5.
Note
For the basic system parameters, I’ve used the default for all but one. Enabling time service certainly isn’t mandatory—I could easily enable ntpd after installation instead. I could have also told the installer to disable X, but I can change that after installation as well.
Now to set up your first user.
Setup a user? (enter a lower-case loginname, or 'no') [no] mwlucas Full user name for mwlucas? [mwlucas] Michael W Lucas Password for mwlucas account? (will not echo) Password for mwlucas account? (again) Since you set up a user, disable sshd(8) logins to root? [yes]
My usual user account name is mwlucas. Here, I enter that username, along with a real name entry. The installer creates this account and gives it permission to use the root password (see Chapter 6). You should be prompted twice for the user’s password.
Note
You’re offered a chance to disable root logins over SSH. Use this default. The root account should never be permitted to log in via SSH, unless using public key authentication, and even then, those logins should be restricted. For the reasons to avoid root logins over SSH, do an Internet search for “Hail Mary Cloud.”
Setting the Time Zone
Set your time zone during installation. If you have Internet access when you install OpenBSD, the installer should try to determine your time zone. OpenBSD assumes that the BIOS clock is set in Coordinated Universal Time (UTC). If the BIOS clock is set in some other time zone, you’ll need to correct the system time after installation.
I’m in Detroit, Michigan. If you’re familiar with US geography, you might think that I need US Eastern Time, but my state has its own time zone.
1 What timezone are you in? ('?' for list) [US/Eastern] ? Africa/ Chile/ GB-Eire Israel NZ-CHAT UCT America/ Cuba GMT Jamaica Navajo US/ Antarctica/ EET GMT+0 Japan PRC UTC Arctic/ EST GMT-0 Kwajalein PST8PDT Universal Asia/ EST5EDT GMT0 Libya Pacific/ W-SU Atlantic/ Egypt Greenwich MET Poland WET Australia/ Eire HST MST Portugal Zulu Brazil/ Etc/ Hongkong MST7MDT ROC posix/ CET Europe/ Iceland Mexico/ ROK posixrules CST6CDT Factory Indian/ Mideast/ Singapore right/ Canada/ GB Iran NZ Turkey 2 What timezone are you in? ('?' for list) [US/Eastern] US 3 What sub-timezone of 'US' are you in? ('?' for list) ? Alaska Central Hawaii Mountain Samoa Aleutian East-Indiana Indiana-Starke Pacific Arizona Eastern Michigan Pacific-New 4 What timezone are you in? ('?' for list) [US/Eastern] US/Michigan
I don’t recall my exact time zone, but I know it isn’t plain old US Eastern Time. I enter a question mark (?) at 1 to see the available options. I don’t recognize any of the time zones listed at 2 as correct for my city, but I know I’m in a US time zone, so I enter US. I don’t know what my choices of sub-time zones are, so I enter a question mark (?) at 3 to see the US time zones. And there’s Michigan! At 4, I enter the full time zone name.[9]
Setting Up the Disk
As noted earlier, in a dedicated installation, the installer erases all data on the drive. Unlike most other operating system installers, the OpenBSD installer doesn’t warn you about this; it assumes that you understand the implications of repartitioning your hard drive.
For this first installation, we’ll use OpenBSD’s default partitioning scheme. (We’ll discuss custom partitioning later in this chapter.) Our demo server has a single disk. We’ll first create an MBR partition on this disk and then add OpenBSD partitions.
Available disks are: sd0. Which one is the root disk? (or 'done') [sd0] Use DUIDs rather than device names in fstab? [yes]
The installer tells us that it sees one disk, device sd0. The installer must know which disk will hold the root partition. (With only a single disk this seems superfluous, but it becomes important if you system has we’ll see an example with multiple disks, as discussed in Custom Disk Layout.) When you have only one disk, OpenBSD assumes that you’ll use it. It also asks if you want to use the disk’s DUID in the filesystem table rather than the device name. For reasons we’ll discuss in Chapter 8, always answer yes to this.
The installer will now show you the MBR partition table.
Disk: sd0 geometry: 6527/ 255/ 63 [ 104857600 Sectors]
Offset: 0 Signature: 0xAA55
Starting Ending LBA Info:
#: id C H S - C H S [ start: size ]
------------------------------------------------------------------------------
0: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
1: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
2: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
3: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
Use (W)hole disk, use the (O)penBSD area, or (E)dit the MBR? [whole]
Setting OpenBSD MBR partition to whole sd0…done.The first line shows the detected hard drive geometry. This particular drive has 6527 cylinders, 255 heads, and 63 sectors per cylinder. If you compare this to the label on the physical drive, it almost certainly won’t match (because hard drives lie). But note that this translated geometry has exactly the same number of sectors as shown in the hard drive documentation.
Beneath this line, you see the existing MBR partition table. The partitions are all zeroed out, which means that this drive has no partitions. We want only OpenBSD on this machine, so take the default and let OpenBSD swallow the whole drive.
Now it’s time to consider your OpenBSD partitions.
The auto-allocated layout for sd0 is:
# size offset fstype [fsize bsize cpg]
1 a: 1.0G 64 4.2BSD 2048 16384 1 # /
b: 1.2G 2097216 swap
c: 50.0G 0 unused
d: 3.6G 4716480 4.2BSD 2048 16384 1 # /tmp
e: 5.7G 12176320 4.2BSD 2048 16384 1 # /var
f: 2.0G 24063040 4.2BSD 2048 16384 1 # /usr
g: 1.0G 28257344 4.2BSD 2048 16384 1 # /usr/X11R6
h: 6.3G 30354496 4.2BSD 2048 16384 1 # /usr/local
i: 1.9G 43566400 4.2BSD 2048 16384 1 # /usr/src
j: 2.0G 47467072 4.2BSD 2048 16384 1 # /usr/obj
k: 25.4G 51661376 4.2BSD 2048 16384 1 # /home
2 Use (A)uto layout, (E)dit auto layout, or create (C)ustom layout? [a]
3 /dev/rsd0a: 1024.0MB in 2097152 sectors of 512 bytes
6 cylinder groups of 202.47MB, 12958 blocks, 25984 inodes each
…Our first partition at 1 is a, which occupies 1GB and will be used as the root partition (/). On the installed system, this will be known as partition sd0a. Look down the list to see all of the standard partitions discussed in Chapter 2.
We could do custom disk partitioning at this point, but for our first installation, we’ll use the defaults, as shown at 2. The installer should then label the disk and 3 create filesystems on all the partitions.
Choosing File Sets
Now that you have allocated disk space, let’s put the operating system onto the disk. The installer starts by asking some basic questions about how to get the sets.
Let's install the sets! Location of sets? (cd disk ftp http or 'done') [cd] 1 ftp HTTP/FTP proxy URL? (e.g. 'http://proxy:8080', or 'none') [none] Server? (hostname, list#, 'done' or '?') [ftp5.usa.openbsd.org] 2 ftp.lambdaserver.com Server directory? [pub/OpenBSD/5.3/amd64] Login? [anonymous]
Although I booted this system off a CD, I’m going to install the file sets via 1 FTP. If my network needed to use a proxy to access the Internet, I would tell the installer.
While the installer will choose an FTP server for you at 2, you can specify an FTP server that you know is close or fast. If you’re installing a snapshot, give the file path to the desired snapshot on the FTP server. Finally, if this FTP server requires a username and password, enter it here.
At this point, the installer should log in to the FTP server, find all available file sets, and display them for your approval.
Select sets by entering a set name, a file name pattern or 'all'. De-select
sets by prepending a '-' to the set name, name pattern or 'all'. Selected
sets are labelled '[X]'.
[X] bsd [X] etc53.tgz [X] xbase53.tgz [X] xserv53.tgz
[X] bsd.rd [X] comp53.tgz [X] xetc53.tgz
[X] bsd.mp [X] man53.tgz [X] xshare53.tgz
[X] base53.tgz [X] game53.tgz [X] xfont53.tgz
Set name(s)? (or 'abort' or 'done') [done]I suggest you install everything, but you can choose to remove one or more sets.
For example, suppose you are building a firewall machine. Firewalls traditionally don’t have compilers, documentation, or X. You can remove file sets by entering a minus sign (-) and the name of the file set.
Set name(s)? (or 'abort' or 'done') [done] 1 -comp53.tgz -man53.tgz [X] bsd [X] etc53.tgz [X] xbase53.tgz [X] xserv53.tgz [X] bsd.rd [ ] comp53.tgz [X] xetc53.tgz [X] bsd.mp [ ] man53.tgz [X] xshare53.tgz [X] base53.tgz [X] game53.tgz [X] xfont53.tgz Set name(s)? (or 'abort' or 'done') [done]
This example removes the compiler and manual file sets at 1. You can see that they’re no longer selected in the list of file sets.
You can also use wildcards when selecting file sets. For example, here’s how to remove all file sets beginning with an x:
Set name(s)? (or 'abort' or 'done') [done] -x*
[X] bsd [X] etc53.tgz [ ] xbase53.tgz [ ] xserv53.tgz
[X] bsd.rd [ ] comp53.tgz [ ] xetc53.tgz
[X] bsd.mp [ ] man53.tgz [ ] xshare53.tgz
[X] base53.tgz [X] game53.tgz [ ] xfont53.tgz
Set name(s)? (or 'abort' or 'done') [done]If you change your mind, you can add file sets back in by entering a plus (+) sign and the file set name. Here, I add back everything by using a wildcard (*):
Set name(s)? (or 'abort' or 'done') [done] *
[X] bsd [X] etc53.tgz [X] xbase53.tgz [X] xserv53.tgz
[X] bsd.rd [X] comp53.tgz [X] xetc53.tgz
[X] bsd.mp [X] man53.tgz [X] xshare53.tgz
[X] base53.tgz [X] game53.tgz [X] xfont53.tgz
Set name(s)? (or 'abort' or 'done') [done]Once you’re ready, press ENTER to install the default or selected file sets.
After the installer unpacks all of the file sets on the hard drive, it will ask if you have more file sets to install.
Location of sets? (cd disk ftp http or 'done') [done]
If you have any custom file sets, you could install them at this point.
Finishing the Installation
After unpacking the file sets, the installer cleans up after itself and tells you it’s finished with this message:
CONGRATULATIONS! Your OpenBSD install has been successfully completed! To boot the new system, enter 'reboot' at the command prompt. When you login to your new system the first time, please read your mail using the 'mail' command.
Do as you’re told and enter reboot, and then remove the CD if necessary. If you’re content with a default installation, you can skip to Chapter 4 now.
Custom Disk Layout
If you have multiple hard disks in a system, or if you want a different partition layout than the default, you must manually edit your disk layout.
The installer partitions one disk at a time, and you can’t easily bounce between multiple disks. To successfully use multiple disks, decide on your partitioning scheme before you start the installation, and write down exactly which partitions you want on which disks as specifically as possible.
My system has two 50GB hard disks. I plan to divide the disks like this:
Disk 1. 1GB /, 1.2GB swap, 5GB /tmp, 1GB /usr/X11R6, 2GB /usr/src, 2GB /usr/obj, and everything else /home
Disk 2. 1GB /altroot, 1.2GB swap, 6GB /var, 10GB /usr/local, and everything else /var/postgresql
This layout includes all of the standard OpenBSD partitions, plus a few additions: I’ve increased some partition sizes above the installer-generated defaults, and I’ve added an extra swap partition on the second hard drive. OpenBSD doesn’t include a separate /var/postgresql partition, but I’ve added one because I want my database data on its own partition. (We’ll discuss the /altroot partition in Chapter 9.)
The installer runs as usual until you get to the disk portion.
Available disks are: sd0 sd1. Which one is the root disk? (or 'done') [sd0]
By default, the installer puts the root partition on the first hard drive, sd0. I’ll use this disk for the root partition and use the entire disk for OpenBSD.
The installer then presents a list of automatically generated disklabel partitions. We don’t want to use these partitions; we want to create our own from scratch.
Use (A)uto layout, (E)dit auto layout, or create (C)ustom layout? [a] cWe want a custom layout, so enter c.
The installer should now drop us to the disklabel(8) command prompt, indicated here by the > symbol:
You will now create an OpenBSD disklabel inside the OpenBSD MBR
partition. The disklabel defines how OpenBSD splits up the MBR partition
into OpenBSD partitions in which filesystems and swap space are created.
You must provide each filesystem's mountpoint in this program.
The offsets used in the disklabel are ABSOLUTE, i.e. relative to the
start of the disk, NOT the start of the OpenBSD MBR partition.
Label editor (enter '?' for help at any prompt)
>We can now use the interactive disklabel editor to create OpenBSD partitions within the MBR partition, as discussed in the following sections.
Viewing Disklabels
The p command prints the partition’s existing disklabel:
> p
OpenBSD area: 64-104856255; size: 104856191; free: 32
# size offset fstype [fsize bsize cpg]
a: 2104448 64 4.2BSD 2048 16384 1
b: 2506143 2104512 swap
c: 104857600 0 unused
d: 10490432 4610656 4.2BSD 2048 16384 1
…
>This is exactly the same information discussed in Understanding Disklabels. This hard drive previously had an OpenBSD installation, and the disklabel has those old partitions.
To display partition sizes in megabytes, enter p m:
> p m
OpenBSD area: 64-104856255; size: 51199.3M; free: 0.0M
# size offset fstype [fsize bsize cpg]
a: 1027.6M 64 4.2BSD 2048 16384 1
b: 1223.7M 2104512 swap
c: 51200.0M 0 unused
d: 5122.3M 4610656 4.2BSD 2048 16384 1
…You can also display partition sizes in gigabytes by entering p g:
> p g
OpenBSD area: 64-104856255; size: 50.0G; free: 0.0G
# size offset fstype [fsize bsize cpg]
a: 1.0G 64 4.2BSD 2048 16384 1
b: 1.2G 2104512 swap
c: 50.0G 0 unused
d: 5.0G 4610656 4.2BSD 2048 16384 1
…Choose the unit of measurement best suited to your disk.
Deleting Partitions
Use the d command to delete partitions:
> d partition to delete: [] a >
That’s it. Tell disklabel to delete a partition on this disk, give it the partition letter, and it’s gone. But beware: disklabel won’t ask you to verify your choice, so be sure to choose the correct partition.
Erasing Existing Disklabels
You could manually delete all partitions, but it’s much easier to zero out the existing disklabel with the z command:
> z > p OpenBSD area: 64-104856255; size: 104856191; free: 104856191 # size offset fstype [fsize bsize cpg] c: 104857600 0 unused >
Here, we tell disklabel to erase the partition table with z, and then print the partition table with p. The output should be an empty disklabel, because the c disklabel partition represents the entire MBR partition. We can now create our desired partitions.
Creating Disklabel Partitions
This first disk needs the following partitions:
1GB / (root)
1.2GB swap
5GB /tmp
1GB /usr/X11R6
2GB /usr/src
2GB /usr/obj
Everything else /home
By default, disklabel creates partitions in order. You can manually create partitions in any order you want, but you’ll need to track sectors and cylinders in order to figure out where each partition should begin and end. I strongly recommend creating partitions in order and letting disklabel do the math.
Use the a command to create a partition beginning with /:
> a 1 partition: [a] 2 offset: [64] 3 size: [104856191] 1g 4 Rounding size to cylinder (16065 sectors): 2104451 5 FS type: [4.2BSD] 6 mount point: [none] / 7 Rounding size to bsize (32 sectors): 2104448 >
By default, at 1, disklabel offers the next free letter for your new partition. The first partition on the disk is a. Press ENTER to accept it.
The offset for a disklabel partition is the number of sectors from the beginning of the disk where the partition starts, not from the beginning of the MBR partition, which is the actual beginning of the disk. The first 63 sectors of a disk, numbers 0 through 62, contain the MBR. We could use sector 63, but OpenBSD starts on sector 64 to better align with memory cells in solid-state disks. At 2, you can see that disklabel offers 64 as the default offset.
The size at 3 is the number of sectors the partition uses. By default, disklabel offers all the remaining space on the disk, but I want a 1GB root partition. I could do the math to figure out how many sectors are in a gigabyte, but I’m lazy, so I use an abbreviation instead. The disklabel command recognizes the following abbreviations for sizes:
bfor bytescfor cylinderskfor kilobytesmfor megabytesgfor gigabytes
All partitions must end on a cylinder boundary, so disklabel figures out the closest boundary and, at 4, sizes my root partition to match. My root partition will be pretty close to 1GB.
The FS type at 5 shows the filesystem used on this partition. For an OpenBSD disk, every data partition needs type 4.2BSD. Your swap partition will be of type swap.
The mount point at 6 is where you want this partition mounted. By default, disklabel doesn’t assign a mount point because it can’t guess what you want. Enter the partition’s mount point.
Partitions must end on a cylinder boundary, but should end with a whole block for the filesystem. The disklabel command 7 adjusts the partition size again, based on the standard block size of the filesystem.
Our next partition is swap space.
> a 1 partition: [b] 2 offset: [2104512] 3 size: [102751743] 1.2g 4 Rounding size to cylinder (16065 sectors): 2506143 5 FS type: [swap] >
The disklabel command assumes at 1 that you’re using the next partition letter, b. It automatically calculates the offset at 2, which is the next free sector after the previous partition. I use decimal fractions at 3 to set the size (I could alternatively enter 1200m). The size at 4 is rounded to the nearest cylinder boundary. Finally, disklabel knows that partition b is traditionally swap space, so it offers 5 that as the default. Swap space doesn’t need a mount point, and it doesn’t have a block size.
We can create the remaining partitions in the same way. Creating the last partition, /home, is even easier:
> a partition: [h] offset: [25575456] 1 size: [79280799] FS type: [4.2BSD] mount point: [none] /home Rounding size to bsize (32 sectors): 79280768 >
As you can see at 1, we don’t need to track how much empty disk space remains, because disklabel does that for us. Press ENTER to swallow it all. Now is your chance to leave empty space on your disk.
Now that you’ve created all your partitions, print the disklabel (with the p command, as described earlier in the chapter) to double-check your work.
Writing the New Disklabel
When you’re satisfied with your partition scheme, enter q to write your disklabel to disk:
> q Write new label?: [y] y /dev/rsd0a: 1027.6MB in 2104448 sectors of 512 bytes …
disklabel gives you one last chance to change your mind. Once you write a new disklabel, recovering any data on the disk becomes extremely difficult, so be sure you backed up any vital data on this disk before starting the installation. (This is a good time to make sure that you didn’t microwave your backup.)
Adding More Disks
After you partition your first disk, the installer offers you a chance to partition any other hard drives:
Available disks are: sd1.
Which one do you wish to initialize? (or 'done') [done] sd1The default is to not partition any other disks. If you choose another disk, you’ll need to create MBR partitions and then disklabel partitions.
Once all of your hard drives have been formatted, you’ll return to installing the file sets.
Advanced Disklabel Commands
While the basic commands should suffice to partition your disk, disklabel supports a variety of advanced commands. We’ll look at a few of them now.
Changing Basic Drive Parameters
Remember all that stuff at the top of the disklabel that shows the drive’s basic physical characteristics? You can change all that, but it’s almost never necessary. In fact, if you think doing this is a good way to solve a problem, you’re probably on the wrong track.
If you enter e, disklabel walks you through each entry on the upper part of the disklabel. The existing values are presented as defaults, allowing you to quickly walk through the variables until you reach the one you want to change:
> e
Changing device parameters for /dev/rsd2c:
disk type: [SCSI]
label name: [Samsung HVX8812]
sectors/track: [63]
…Edit this information at your own risk because you can render your disk unbootable or your partitions unusable by changing it! Changing the drive’s physical description means you’re lying to your computer, and computers go ballistic when you lie to them about their hardware.
Modifying Existing Partitions
The m command modifies existing partitions. The disklabel tool walks you through each of the values you entered when creating the disk, offering your original values as defaults and allowing you to change them. But most of the time, it’s easier to just delete the partition and re-create it.
Entering Expert Mode
Expert mode gives the advanced user access to some rarely used options in disklabel. Most people don’t need these and find them simply clutter. (It’s not as if disklabel isn’t complicated enough already.)
To access expert mode, use the X command. You won’t immediately see all of the options available, but entering other commands will produce more options and more output.
Getting More Help
You can enter a single question mark (?) at the disklabel prompt for a brief list of all available commands. If you want more detailed help, the M command displays the disklabel(8) man page.
You’ve now installed OpenBSD. Let’s see what to do next.
[8] Yes, some of us have half-suppressed memories of i386 hardware that couldn’t boot OpenBSD from a CD, but would let you fetch the install sets from one once you had it boot from a floppy. But seriously, if your hardware is that aged and picky, please save yourself some pain. Go back to the dumpster you found that computer in. Find something more recent.
[9] Of course, the US/Michigan time zone applies only to the four counties on the west end of the Upper Peninsula. But accepting the default wouldn’t let me illustrate this, and if I have to make something up, it might as well be vaguely plausible.