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Revision 6 as of 2006-02-16 23:10:22
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Editor: ?DavideViti
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Editor: ?DavideViti
Comment: Added instruction for performing a floppy install
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$ qemu -cdrom mini.iso -hda hd_image.img -boot d $ qemu -user-net -cdrom mini.iso -hda hd_image.img -boot d
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 * "eject" is useful when you want to (virtually) change disk
  (for example you want to use another iso image)
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= Floppy install =
To test an installation from the floppy images, you first need to grab [http://people.debian.org/~joeyh/d-i/images/daily/floppy/boot.img boot.img] and [http://people.debian.org/~joeyh/d-i/images/daily/floppy/root.img root.img]
and use the files as if they were floppy disks:

{{{
$ qemu -user-net -fda boot.img -hda hd_image.img -boot a
}}}

once you're asked to insert the root disk, just switch to "monitor" (ctrl-alt-2) and

{{{
(qemu) change fda root.img
}}}

switch back to d-i (ctrl-alt-1) and press ENTER

Resources

[http://fabrice.bellard.free.fr/qemu/ Official page]

#qemu IRC channel on irc.freenode.net

Intro

Qemu can be used to simulate various hardware configurations and to easily test the debian installer in various conditions; it's great for testing "delicate" things like a partitioner, since disk devices are usually represented by files.

It can be used also to emulate other architectures: I tested amd64 and powerpc versions on the installer on my i386 host machine. At the moment (qemu-0.8.0) sparc and ARM are being worked on and have some basic support.

Here some possible d-i boot configurations:

  • floppy installs
  • installs from USB (??)
  • lowmem installs

Basic setup

First of all, you need to create a file which will acts as an hard disk for the virtual machine:

$ qemu-img create hd_img.img 500M

You can then download an iso image of the installer, or create one yourself; you can then run a g-i session by running the following command:

$ qemu -user-net -cdrom mini.iso -hda hd_image.img -boot d

Qemu monitor

Qemu has a "monitor" (ctrl-alt-2) which can be used to access various funcionalities such as:

  • "screendump" which can be used to take a screenshot of
    • the VM screen
  • "sendkey" is very useful when you want to switch to VT2 during
    • a g-i vession ("sendkey ctrl-alt-f2)
  • "gdbserver" is useful for attaching gdb to a process running inside
    • the VM
  • "loadmem/savemem" used to save/restore the state of the VM, saves you alot
    • of time when you have performed all the steps needed to reproduce a bug

Floppy install

To test an installation from the floppy images, you first need to grab [http://people.debian.org/~joeyh/d-i/images/daily/floppy/boot.img boot.img] and [http://people.debian.org/~joeyh/d-i/images/daily/floppy/root.img root.img] and use the files as if they were floppy disks:

$ qemu -user-net -fda boot.img -hda hd_image.img -boot a

once you're asked to insert the root disk, just switch to "monitor" (ctrl-alt-2) and

(qemu) change fda root.img

switch back to d-i (ctrl-alt-1) and press ENTER