Sometimes, especially with older drives, the installer may fail to boot from an optical disc. The installer may also — even after booting successfully from such disc — fail to recognize the disc or return errors while reading from it during the installation.

There are many different possible causes for these problems. We can only list some common issues and provide general suggestions on how to deal with them. The rest is up to you.

There are two very simple things that you should try first.

If this does not work, then try the suggestions in the subsections below. Most, but not all, suggestions discussed there are valid for CD-ROM and DVD.

If you cannot get the installation working from optical disc, try one of the other installation methods that are available.

If you have problems and the kernel hangs during the boot process, doesn't recognize peripherals you actually have, or drives are not recognized properly, the first thing to check is the boot parameters, as discussed in Section 5.3, “Boot Parameters”.

In some cases, malfunctions can be caused by missing device firmware (see Section 2.2, “Devices Requiring Firmware” and Section 6.4, “Loading Missing Firmware”).

During the boot sequence, you may see many messages in the form can't find something, or something not present, can't initialize something, or even this driver release depends on something. Most of these messages are harmless. You see them because the kernel for the installation system is built to run on computers with many different peripheral devices. Obviously, no one computer will have every possible peripheral device, so the operating system may emit a few complaints while it looks for peripherals you don't own. You may also see the system pause for a while. This happens when it is waiting for a device to respond, and that device is not present on your system. If you find the time it takes to boot the system unacceptably long, you can create a custom kernel later (see Section 8.5, “Compiling a New Kernel”).

If you get through the initial boot phase but cannot complete the install, the menu option Save debug logs may be helpful. It lets you store system error logs and configuration information from the installer on a storage medium, or download them using a web browser. This information may provide clues as to what went wrong and how to fix it. If you are submitting a bug report, you may want to attach this information to the bug report.

Other pertinent installation messages may be found in /var/log/ during the installation, and /var/log/installer/ after the computer has been booted into the installed system.

If you still have problems, please submit an installation report. We also encourage installation reports to be sent even if the installation is successful, so that we can get as much information as possible on the largest number of hardware configurations.

Note that your installation report will be published in the Debian Bug Tracking System (BTS) and forwarded to a public mailing list. Make sure that you use an e-mail address that you do not mind being made public.

If you have a working Debian system, the easiest way to send an installation report is to install the installation-report and reportbug packages (apt install installation-report reportbug), configure reportbug as explained in Section 8.4.2, “Sending E-Mails Outside The System”, and run the command reportbug installation-reports.

Alternatively you can use this template when filling out installation reports, and file the report as a bug report against the installation-reports pseudo package, by sending it to <submit@bugs.debian.org>.

Package: installation-reports

Boot method: <How did you boot the installer? CD/DVD? USB stick? Network?>
Image version: <Full URL to image you downloaded is best>
Date: <Date and time of the install>

Machine: <Description of machine (eg, IBM Thinkpad R32)>
Processor:
Memory:
Partitions: <df -Tl will do; the raw partition table is preferred>

Output of lspci -knn (or lspci -nn):

Base System Installation Checklist:
[O] = OK, [E] = Error (please elaborate below), [ ] = didn't try it

Initial boot:           [ ]
Detect network card:    [ ]
Configure network:      [ ]
Detect media:           [ ]
Load installer modules: [ ]
Detect hard drives:     [ ]
Partition hard drives:  [ ]
Install base system:    [ ]
Clock/timezone setup:   [ ]
User/password setup:    [ ]
Install tasks:          [ ]
Install boot loader:    [ ]
Overall install:        [ ]

Comments/Problems:

<Description of the install, in prose, and any thoughts, comments
      and ideas you had during the initial install.>

In the bug report, describe what the problem is, including the last visible kernel messages in the event of a kernel hang. Describe the steps that you did which brought the system into the problem state.