Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.bugs.dist > #1148313

Bug#1036918: debvm: manual mounting of root image

Show all headers | View raw

Hi Wouter,

On Mon, May 29, 2023 at 02:20:09PM +0200, Wouter Verhelst wrote:
> I am exploring the possibility to write an autopkgtest for the initramfs
> stuff that I wrote for nbd-client.

Please see my other mail regarding the use of debvm in autopkgtests.
Let's not duplicate that topic here. I note that this fully applies in
the exact way to the projected use of mmdebstrap below.

> In order to do so, I want to run a client VM that has no root hard disk
> configured, but is configured to attempt to mount the VM image over the
> network, using NBD. This is accomplished by way of a few kernel command
> line parameters.
> 
> I tried running
> 
> debvm-run -- -append 'nbdroot=192.168.88.103,root_export,nbd0'

May I suggest that this is a quite unusual use case and that debvm may
not be the right hammer for your job? While debvm gives you a complete
rootfs, you seem to be satisfied with a kernel an an initrd. How about
peeking at debvm's source and extracting the useful bits from it? In
effect you can skip much of what debvm does and construct a manageable
mmdebstrap invocation directly. The following draft is entirely
untested:

mmdebstrap \
	--variant=apt \
	unstable \
	/dev/null \
	--include=linux-image-"$(dpkg --print-architecture)" \
	--customize-hook="download /initrd ./initrd" \
	--customize-hook="download /vmlinuz ./vmlinuz"

> I would like to see an option to tell debvm-run not to mount the
> filesystem image but to let the user handle that. However, the
> extracting of the kernel and initramfs which debvm-run does would still
> be necessary; it's just that I want to fiddle with how we get to the
> filesystem.

Given the images, I think you can pass them to qemu directly. Do you
agree that for this use case, using the underlying tools directly does a
better job?

Helmut

Back to linux.debian.bugs.dist | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Bug#1036918: debvm: manual mounting of root image Wouter Verhelst <wouter@debian.org> - 2023-05-29 14:30 +0200
  Bug#1036918: debvm: manual mounting of root image Helmut Grohne <helmut@subdivi.de> - 2023-05-29 20:30 +0200
    Bug#1036918: debvm: manual mounting of root image Wouter Verhelst <w@uter.be> - 2023-05-31 12:30 +0200
      Bug#1036918: debvm: manual mounting of root image Helmut Grohne <helmut@subdivi.de> - 2023-06-01 08:00 +0200
        Bug#1036918: debvm: manual mounting of root image Wouter Verhelst <w@uter.be> - 2023-06-01 10:40 +0200

csiph-web