On Mon, Apr 25, 2022 at 02:42:18PM +0200, Nguetchouang Ngongang Kevin wrote: > Hello everyone, i got 2 questions and I hope you could help me ? > * is it possible to specify extra options of qemu-img (when > creating/building image/os using virt-install and virt-builder ?) Could be useful to know what particular options you are interested in. Maybe qemu-img create "-o" stuff? > * Is it possible to rebuild another os (in the manner of > virt-builder) on an existing image file but by using virt-customize? I'm not totally sure what this question means. virt-builder is really a tool that downloads and uncompresses templates (from: https://builder.libguestfs.org/ and other places) and then customizes them using the same code as used in virt-customize. So you can split up the two tasks yourself easily enough, if that's what you mean. Virt-customize can be used across many different OSes. Rich.

On Mon, Apr 25, 2022 at 04:40:15PM +0200, Nguetchouang Ngongang Kevin wrote: > I want to achieve the external data file creation > > "qemu-img create -o data_file_raw=on,data_file=path/to/file" > > but there is no way to specify those options while using virt-builder. Interesting - I had no idea about this feature before. At the moment it's not possible to do this within virt-builder, without patching virt-builder. I guess maybe you can post-convert the file after virt-builder has run? I grepped the source of virt-install and it doesn't seem like it has support either. Nor does libvirt. It should be possible to use virt-customize on these special qcow2 files, although I didn't try it. Rich.

On Mon, Apr 25, 2022 at 04:11:59PM +0100, Richard W.M. Jones wrote: > On Mon, Apr 25, 2022 at 04:40:15PM +0200, Nguetchouang Ngongang Kevin wrote: > > I want to achieve the external data file creation > > > > "qemu-img create -o data_file_raw=on,data_file=path/to/file" > > > > but there is no way to specify those options while using virt-builder. > > Interesting - I had no idea about this feature before. > > At the moment it's not possible to do this within virt-builder, > without patching virt-builder. I guess maybe you can post-convert the > file after virt-builder has run? > > I grepped the source of virt-install and it doesn't seem like it has > support either. Nor does libvirt. > > It should be possible to use virt-customize on these special qcow2 > files, although I didn't try it. I talked to Kevin and apparently this feature was added to qemu to

support a particular downstream project (oVirt), but in the end they didn't use it and also support was never added to libvirt. So it doesn't particularly sound like this is a well tested or widely used feature ... Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html