Re: [Libguestfs] translating CD-ROM device paths from i440fx to Q35 in virt-v2v (was: test-v2v-cdrom: update the CD-ROM's bus to SATA in the converted domain)

On Thu, Sep 30, 2021 at 01:12:39PM +0200, Laszlo Ersek wrote: The input is not always (in fact, hardly ever) full libvirt XML. It's input specific to the hypervisor. For VMware it might be: - the *.vmx file (the real source of truth) (-i vmx) - partial libvirt XML generated by libvirt's vpx driver, but this is derived from information from VMware APIs and ultimately that comes from the *.vmx file (-i libvirt -ic esx:// or -ic vpx://) - the *.ovf file (-i ova) - nothing at all! (-i disk) Also we don't currently try to find or rewrite /dev/disk/ paths in guest configuration files. The only rewriting that happens is for /dev/[hs]d* block device filenames and a few others. The actual code that does this is convert/convert_linux.ml:remap_block_devices So I wouldn't over-think this. It's likely fine to identify such devices and rewrite them as "/dev/cdrom", assuming that (I didn't check) udev creates that symlink for any reasonably modern Linux. And if there's more than one attached CD to the source, only convert the first one and warn about but drop the others. Note that the aim of virt-v2v is to make it boot on the target, make sure the network works, and get the user to a login prompt. The MTV management app around virt-v2v allows site-specific pre- and post- configuration to happen (site-specific Ansible playbooks). There also exists ssh and remote console. For people using virt-v2v on the command line, if they get the guest to boot on the target and not every device fully works, there is an expectation that they can log in as root and fix small[*] things. Rich. [*] Obviously if the boot / system is completely broken, not that. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top