Is there a Gentoo raw / Virtual Machine Image Creation Tool?

[adrelanos]

Is there a tool to create bootable raw images?

Or is there a tool to create bootable virtual machine images?

All in an automated / scripted fashion.

Similar to these Debian / Ubuntu specific tools:
- grml-debootstrap: http://grml.org/grml-debootstrap
- vmdebootstrap: http://liw.fi/vmdebootstrap
- Kameleon: http://wiki-oar.imag.fr/index.php/Kameleon
- VMBuilder: https://launchpad.net/vmbuilder
_________________
...

[szatox]

I've been looking for a similar tool.

To make me happy it must:
- be easy and quick to run
- provide up-to-date system
- not require agent inside OS to be assembled.

So far I'm fairly happy about portage for the hard part - building up-to-date image - even though I'm still figuring it out.
Anyway, here what I have right now:
build directory contains:
etc/portage/ target/

etc/portage is there to let me have different keywords, use and mask atributes than host.

Components necessary to create a new system image:
- baselayout (USE build - important)
- stuff you want to have installed
optionaly:
- kernel (copy from host's /boot - or prepare dedicated kernel image on host. I'm not going to recompile it inside VM anyway )

to build new system use:
emerge -bk --config-root=./ --root=target/ baselayout <desired stuff>
Notice: the created system will not be self-sufficient. There will be no portage, no headers, etc. Just a single-purposed dummy.

Anyway, after emerge completes, it would be handy to tune configs a bit. E.g. creating users, changing passwords or enabling serial console. Probably sed or patch would do the trick.

Now, there are many ways to stuff that system into a VM. Raw image is one (reasonably easy to prepare), PXE is another (even easier, once you have all servers set up), qemu also supports direct boot, never tried it but there might not be any need to stuff it into an image at all. This being said, i'm gonna yet figure out what way of booting will be the most convenient. Qcow is interesting as it provides snapshots and live migration (also migration to a file, so we can dump the whole running VM to disk)

[Ant P.]

You don't need distro-specific hacks to do this with Gentoo - just create the VM disk image, partition and mount it using qemu-nbd, then do a normal chroot install. (You could also try a non-chroot install from the host using the $ROOT variable, but that's undocumented.)

[adrelanos]

[szatox]

Ah, so that's the problem for you. Ok, here's a tip on turning filesystems into images:

[NeddySeagoon]

szatox,

You can even chroot into the image to install your boot loader so it just works when you boot the VM.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Progman3K]

[KaZeR]

Have a look at this script to build an image :
https://github.com/pgrandin/builder/blob/master/build_ami.sh

and this one for an arm example ( raspberry pi )
https://github.com/pgrandin/builder/blob/master/build_pi.sh

(the last one builds a stage 4 but it's easy to adapt it to build a disk image instead )
_________________
Foo.

[NeddySeagoon]

Progman3K,

You can't use grub on ARM, its full of Intel 16 bit (real mode) and 32 bit asm.

However qemu can emulate ARM, so you can do any steps that need to be done inside the VM in qemu.
It will be slow but it still works.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Progman3K]

[szatox]

What about easy mode AKA user mode?
Don't provide any params regarding networking, it should use some defaults allowing your guest OS access the internet the same way any application could. You won't be able to access guest os from your pc, but this often is a minor problem.