Debian on CD

Frequently Asked Questions

What is a CD image anyway?

A CD image is the exact representation of the data on a CD in a normal computer file, that can e.g. be transmitted over the Internet. CD burning programs can use the image files to make real CDs.

In Debian, we use the term CD image as a common way to describe a range of things, many of which don't even fit on CD! The name is old, but it has stuck. We regularly build multiple different types of image:

In many cases, these installer and live images can often be written directly to USB flash drives with no CD involved; see below. Don't be put off by the name CD image!

For a correctly written image, the .iso file must not appear on the media when you access it! Instead, you should see a number of files and directories - in the case of a Debian installer image, this includes a dists directory and a README.html file.

The .iso format we use for our images is roughly comparable to a .zip file: It contains other files and directories, and only these will appear on the final USB/CD/DVD medium. Some archive programs allow you to unpack .iso files. Do not use this feature to create a USB/CD/DVD from the unpacked files! The resulting medium will fail to boot because the .iso format includes special information related to booting from the USB/CD/DVD, which is lost when you unpack the file. See below on how to correctly write a CD/DVD image under Linux, Windows or Mac OS, or how to write an image to a USB flash drive.

My question is not answered by this FAQ!

If you cannot find an answer to your question here, you can ask for help on one of the Debian mailing lists. In all cases, you should search the mailing list archives before sending mail to the lists. You can subscribe to and unsubscribe from the lists. However, you do not need to be subscribed in order to send mail to the lists - if you are not subscribed, ask for replies to be CC'd to you.

Mailing lists relevant to problems with CD installation:

Why should I use this jigdo program? I prefer a simple HTTP download!

Today, there are nearly 300 Debian mirrors (which contain the complete Debian distribution as .deb files), and machines serving Debian CD images.

Additionally, nobody is very enthusiastic about setting up more CD servers because of the tremendous amounts of wasted bandwidth (some people keep restarting failed downloads instead of resuming from the point where the connection was closed) and because a regular mirror is more attractive (it allows continuous upgrades of Debian, or using the testing/unstable distribution instead of the stable one).

jigdo tries to make the most out of this situation, by downloading the data for the CD images from one of the 300 mirrors. However, these mirrors only hold individual .deb files, not the CD image, so some additional manipulation of the data is necessary to produce one big CD image file from the many small .deb files.

Do not be afraid to try out jigdo! The complex process of generating the CD image is completely hidden from you - instead, you benefit from the fact that one of the 300 Debian mirrors is bound to be nearer and faster than any of the CD servers.

Which of the numerous images should I download? Do I need all of them?

No. First, of course you only need to download CD or DVD or BD images - the three types of images contain the same packages.

Also, you only need the USB/CD/DVD/BD images for your computer's architecture. The architecture is the type of hardware your computer uses. By far the most popular one is the 64-bit Intel/AMD PC architecture, so most people will only want to get the images for amd64. If your PC has an older 32-bit AMD or Intel processor, you will most likely need the i386 images instead.

Furthermore, in most cases it is not necessary to download all of the images for your architecture. The packages are sorted by popularity: The first USB/CD/DVD/BD contains the installation system and the most popular packages. The second one contains slightly less popular ones, the third one even less popular ones, etc. You will probably only need the first couple of DVDs (or the first BD, etc.) unless you have very special requirements. (And in case you happen to need a package later on which is not on one of the USBs/CDs/DVDs/BDs you downloaded, you can always install that package directly from the Internet.)

Please also read the next paragraphs to determine whether you want/need to download network install CDs, update CDs or source CDs.

What is a netinst or network install CD?

To quote the network install page: A network install or netinst CD is a single CD which enables you to install the entire operating system. This single CD contains just the minimal amount of software to install the base system and fetch the remaining packages over the Internet.

If you only want to install Debian on a single machine which has a fast Internet connection, the network install may be the fastest and easiest option for you: You only download the packages that you selected for installation on your machine, which saves both time and bandwidth.

What are the update USBs/CDs/DVDs?

Update USBs/CDs/DVDs are USBs/CDs/DVDs which contain all the packages that changed between a major release version (e.g. 7.0, 8.0, etc.) and a later point release of that stable distribution. For example, if you already have the full set of debian-8.0.0 USBs/CDs/DVDs, you can add the debian-update-8.2.0 disc set to turn this debian-8.0.0 set into a debian-8.2.0 set.

This type of USB/CD/DVD is intended for vendors having large amounts of pressed versions of USBs/CDs/DVDs (which makes them cheaper than individually burned USBs/CDs/DVDs). If you order USBs/CDs/DVDs from such a vendor, it is possible that you'll receive USBs/CDs/DVDs for a slightly older point release, plus some update USBs/CDs/DVDs for the latest revision. This is a perfectly acceptable way of distributing Debian on USB/CD/DVD.

Of course, this type of USB/CD/DVD can also be useful to you as an end user; instead of creating the full set of USBs/CDs/DVDs for each new revision of a release, you only need to download and burn update USBs/CDs/DVDs for your architecture.

Note that update USBs/CDs/DVDs are not meant to boot, they just contain the packages needed to upgrade an existing installation. If you don't have that existing installation, then you'll need to use the normal installation USBs/CDs/DVDs. After the new system is booted, the updated USB/CD/DVD can be added with apt-cdrom add.

Now, what if for some reason you do not want to download the update USB/CD/DVD even though you already have the full set of USBs/CDs/DVDs/BDs for the previous revision? In this case, you should consider using jigdo's update feature: jigdo can read the contents of the old USBs/CDs/DVDs/BDs, download only those files that have changed for the new USBs/CDs/DVDs, and create the full set of new USBs/CDs/DVDs/BDs. Still, it will have done this by downloading only about the same amount of data as for an update USB/CD/DVD.

What are the source CDs?

There are two types of images, the binary CDs that contain precompiled, ready-to-run programs, and the source CDs that contain the source code for the programs. The vast majority of people do not need the source CDs; you should not download them unless you really have a good reason for it.

Where is the CD image with non-free?

Debian has a quite strict view with regard to the licenses of software: Only software that is Free in the sense of the Debian Free Software Guidelines is allowed into the actual distribution. All the other, non-free software (for example, software for which source code is not available) is not supported officially.

The official CDs may freely be used, copied and sold by anyone anywhere in the world. Packages of the non-free category have restrictions that conflict with this, so these packages are not placed on the official CDs.

Sometimes, someone is kind enough to create unofficial non-free CDs. If you cannot find any links on this website, you can try asking on the debian-cd mailing list.

What's the difference between official and unofficial images?

Official images are built by a member of the Debian CD team and have undergone some testing to ensure they work. Once they have been released, the images never change - if they turn out to be broken, a new set with a different version number is released.

Unofficial images can be built by anyone - CD team members, other Debian developers or even advanced Debian users. Typically, they are more up-to-date, but have received less testing. Some have new features (e.g. installation support for new hardware), or contain additional software packages which are not part of the Debian archive.

Is a Debian live image available?

Yes. A so-called live image (live CD), or more precisely, a live system, is a complete system prepared for a DVD, USB key or other medium. You do not need to install anything on the hard drive. Instead you boot from the medium (DVD or USB key) and are able to start working on the machine right away. All programs run directly from the medium.

The Debian Live Project produces live image files for a variety of system types and media.

The USB/CD/DVD/BD fails to boot! / From which disc should I boot?

Only the first USB/CD/DVD/BD in a set is bootable.

If your Debian disc fails to boot, first ensure that you have correctly written it to the medium - please see the explanation above. Additionally, please check whether your BIOS is set up to boot from your optical or USB drive.

Where are the images for M68K, Hurd or other architectures?

Depending on the state of support for a certain architecture, USB/CD/DVD images are available from different places:

Are images for the unstable distribution available?

There are no unstable full USB/CD/DVD/BD images. Due to the fact that the packages in unstable change so quickly, it is more appropriate for people to download and install unstable using a normal Debian HTTP mirror.

If you are aware of the risks of running unstable, but still want to install it, you have a few choices:

Which USB/CD/DVD/BD image contains package XYZ?

To find out which image contains a certain file, use the cdimage search tool. It has knowledge of just about all the Debian USBs/CDs/DVDs/BDs produced by Debian since the 3.0 (Woody) release, covering all the official releases (both older archived releases and the current stable release) and the current sets of daily and weekly testing builds.

Can I have a list of all the packages contained in an image?

Yes. Look on cdimage.debian.org for the corresponding .list.gz file - it will list all the packages and source files included in the image. For Debian Live images, you can find in the same directory as the image files some similarly named files suffixed with .packages. Download these and then search them for the desired package name.

The software on the official CDs is outdated - why don't you release a new version?

We only make official releases of the stable distribution when we think they truly deserve that name. Unfortunately, this means that stable releases only happen about every 2 years...

If you require more recent versions of some of the software in Debian, you can install stable and then upgrade (via the net) those parts you want to the versions from testing - it is possible to mix software from the different releases.

Alternatively, try out the images of testing that are generated automatically every week. More information about testing security support is available from the security FAQ.

If you only need newer versions of specific packages, you can also try the backports service, which takes packages from testing and modifies them to work on stable. This option may be safer than installing the same package directly from testing.

How do I know if I am downloading the newest images?

The note at the bottom of the Debian on CD page always shows the version number of the latest release.

How can I verify the downloaded ISO images and written optical media?

Detailed information on how to authenticate the signed checksum files containing the checksums of the ISO image files is available on the authenticity verification page. After cryptographically verifying the checksum files, we can check that:

The problem with the verification of written optical media is that some media types will possibly return more bytes than those found in the ISO image. This trailing garbage is impossible to avoid with CD written in TAO mode, incrementally recorded DVD-R[W], formatted DVD-RW, DVD+RW, BD-RE, and also with USB keys. Therefore, we need to read exactly the same number of sectors of data from the media as are found in the ISO image itself; reading any more bytes from the media will alter the checksum result.

Alternatively, there is a useful helper script called check_debian_iso which can verify ISO image files and optical media, reading the appropriate amount of bytes from media then computing the checksum and comparing it against the checksum file.

Why is my downloaded DVD image smaller than 1 GB when it should be larger than 4 GB?

Most likely, the tool you use for downloading the image does not have large file support, i.e. it has problems downloading files larger than 4 GBytes. The usual symptom for this problem is that when you download the file, the file size reported by your tool (and the amount of data that it downloads) is too small by exactly 4 GB. For example, if the DVD image is 4.4 GB, your tool will report a size of 0.4 GB.

Some old versions of wget also suffer from this problem - either upgrade to a version of wget which does not have this restriction or use the curl command line download tool: curl -C - [URL]

How do I write an ISO image under Linux/Unix?

Note that Debian ISO images for i386, amd64 and arm64 are also bootable from a USB key; see below.

xorriso for all optical media types (also doable as non-root user):
xorriso -as cdrecord -v dev=/dev/sr0 -eject debian-x.y.z-arch-MEDIUM-NN.iso
In order to get the full nominal speed when writing to BD-RE (i.e. without the slowdown caused by the drive's internal defect management), add the option stream_recording=on.

growisofs for DVD and BD optical media types:
growisofs -dvd-compat -Z /dev/sr0=debian-x.y.z-arch-MEDIUM-NN.iso

wodim for CD optical media type:
wodim -v dev=/dev/sr0 -eject -sao debian-x.y.z-arch-CD-NN.iso

For Linux, there are also the X programs Brasero, K3B and X-CD-Roast, to name a few. Note that they're all frontends to the previously mentioned low-level burning applications.

Brasero
Select the button Burn Image. Then click on Click here to select a disc image, browse and select your downloaded ISO file, check whether the settings under Properties are correct and choose Create Image.
K3b
Select the menu entry Tools - CD - Burn CD Image. In the dialog that opens, enter the path to the image in the Image to Burn field, check whether the other settings are correct, then click on Start.
X-CD-Roast
After the program has started, click on Setup and choose the HD settings tab. Copy the Debian CD image to one of the directories that are displayed in the table. (If the table is empty, enter the path of a directory you want to use for temporary storage, and click on Add.) Click on OK to exit the setup. Next, select Create CD and then Write Tracks. Choose the Layout tracks tab, select the line displaying the image filename and click on Add, then click on Accept track layout. Finally, click on Write tracks.

How do I write an ISO image under Windows?

On recent versions of Windows, this can be done natively by right-clicking the ISO and selecting "Burn image to disk (or similar)"

This might be a little problem on older versions of Windows, as many Windows image-burning programs use their own formats for CD images. To burn the .iso images you will most likely have to use a special menu. Look for options like ISO9660 file, Raw ISO image or 2048 bytes/sector. (Note: other bytes/sector values are fatal!) Some programs do not offer these choices; use another burning program instead (ask a friend or colleague). Here is some information about how to write CD images with specific products:

ImgBurn (Freeware)
There are screenshots of how to write an image to CD/DVD
CDBurnerXP Pro (Freeware)
The process of writing an .iso image is described in the program's manual.
Roxio Easy-CD Creator
From the File menu, choose Create CD from image.... Then select the .iso file type, and the correct image. This opens up the CD creation setup GUI, from there ensure that all the information for your CD-R is correct. In the Create options portion, choose Create CD; under Write method, choose Track at once and Close CD.
Nero from Ahead Software
Disable the Wizard, then select Burn Image from the File or Recorder menu. Select All Files in the file selection window if necessary. Select the .iso file, click OK in the this is a foreign file dialogue box, in case one is displayed. In the option box that opens, the defaults should be okay: Data Mode 1, Block Size 2048, Raw Data, Scrambled, and Swapped not selected, and Image Header and Image Trailer left at 0. Click OK. Under Write CD or Burn, use the default options, e.g. Write and Determine maximum speed, plus check the Finalize CD option.
Microsoft Resource Kit Tools
The command-line Resource Kit Tools are provided by Microsoft free of charge, they work with Windows 2003 and XP. Two programs to write images to CD and DVD are included, they are named Cdburn.exe and Dvdburn.exe. Usage of the programs is described in the accompanying help file - essentially, the command to be executed is something like cdburn drive: iso-file.iso /speed max

If you can provide updated information or details for other programs, please let us know.

How do I write an ISO image under Mac OS?

The Toast program for Mac OS is reported to work fine with .iso files. You can be extra-safe by giving it the creator code CDr3 (or possibly CDr4) and type code iImg using e.g. FileTyper. Double-clicking on the file will then open up Toast directly, without having to drag-and-drop or go via the File-Open menu.

Another option is Disk Utility (included with Mac OS X 10.3 and higher): After opening the Disk Utility application (in the /Applications/Utilities folder), select Burn... in the Image menu and choose the CD image to burn. Ensure that the settings are correct, then click on Burn.

Another option is Disk Copy (included with Mac OS X 10.1 and higher): After opening the Disk Copy application (in the /Applications/Utilities folder), select Burn Image... in the Image menu and choose the CD image to burn. Ensure that the settings are correct, then click on Burn.

How do I write a USB/CD/DVD/BD image to a USB flash drive?

Several of the Debian and Debian Live images, notably all i386, amd64 and arm64 images, are created using the isohybrid technology, which means that they may be used in two different ways:

On a Linux machine, simply use the cp command, to copy an image to a USB flash drive:

cp <file> <device>

Alternatively you can also use dd:

sudo dd if=<file> of=<device> bs=16M status=progress oflag=sync

where:

Please note, that Debian advises not using unetbootin for this task. It can cause difficult-to-diagnose problems with booting and installing, so is not recommended.

How do I write a USB/CD/DVD/BD image on Windows to a USB flash drive?

For Windows users we recommend to use balenaEtcher.

How should I label the discs?

There is no obligatory way of labeling. However, we suggest you use the following scheme to ensure interchangeability:

Debian GNU/{Linux|Hurd} <version>[<revision>]
Official {<architecture>} {CD|DVD|BD}-<number>

For example:

Debian GNU/Linux 6.0.3
Official i386 CD-1

Debian GNU/Linux 6.0.3
Official amd64 DVD-2

Debian GNU/Linux 6.0.3
Official source BD-1

Debian GNU/Hurd 6.0.3
Official i386 Netinst CD

If you have enough space, you can also add the codename to the first line, as in: Debian GNU/Linux 6.0.3 Squeeze.

Note that you are allowed to use the Official designation only on CDs the image of which has a checksum that matches the one from the jigdo files of official releases. Any CD that has no matching checksum (e.g. your own creations) must be clearly labelled as Unofficial, for example:

Debian GNU/Linux 6.0.3
Unofficial Non-free

In the case of official weekly snapshots, version numbers like 6.0.3 should not be used to avoid confusion with released Debian versions. Instead, label the image with a codename like etch or a distribution name like testing. Also add Snapshot and the date of the snapshot to help identify it:

Debian GNU/Linux etch
Official Snapshot alpha Binary-2
2005-06-17

Are old USB/CD/DVD/BD images still available?

Some older images are available from the archive section on cdimage.debian.org. For example, you might want to try out older images if you need support for a certain (sub)architecture which has been dropped for a newer release.

Note that when you install using a really old USB/CD/DVD (pre 4.0, Etch), the contents of /etc/apt/sources.list will reference the current stable Debian release by default. This means that any upgrade over the net will upgrade to the current stable release.

What is the best way of installing Debian on many interconnected computers?

If you want to install Debian on a large number of machines and then keep all these installations up-to-date (e.g. security updates), installing from optical media is not ideal, but then neither is installing via the Internet, because the packages will have to be downloaded again for each machine. In this case, you should set up a local cache, the three options being:

Installing on a large number of machines can be tricky. Fully automatic installation (FAI), provides a web service for creating customized installation images, that may help you with this task.

I have a local Debian mirror and want to create my owns USBs/CD/DVDs/BDs. How do I do this?

Apart from a local Debian mirror, you also need plenty of disc space. The image creation scripts are packaged in the debian-cd package. However, it is usually a better idea to use the latest code from git. (Still, you should have a look at the package's dependencies to ensure you have all the necessary tools.)

To get the latest git version, make sure you have git installed. From an empty directory, give the following command:

git clone https://salsa.debian.org/images-team/debian-cd.git

Should you try to use the scripts, check the debian-cd mailing list archive for solutions to the questions that will inevitably show up. :-)

How do I become a mirror for Debian USB/CD/DVD/BD images?

The necessary steps to set up your debian-cd image mirror and keep it up to date are described on a separate page.

Some Images are missing! Only the first n images are available! Where is the rest?

We don't store/serve the full set of ISO images for all architectures, to reduce the amount of space taken up on the mirrors. You can use the jigdo tool to recreate the missing ISO images instead.