Re: [libvirt] [libguestfs] Options for hotplugging

On Tue, Aug 21, 2012 at 10:32:51AM +0100, Daniel P. Berrange wrote: I maybe wasn't completely clear. We only (currently) do the mapping for parameters. Return values contain the kernel device names. So we don't rewrite the output of guestfs_list_devices, we just suppress the device corresponding to the appliance root filesystem. This both is and isn't a problem at the moment. If you treat the returned strings as opaque blobs, you can pass them back to API functions. However if you want to print them it's a different matter, and lots of tools try to canonicalize the names before printing them, eg: consider the following code in an old version of virt-filesystems: https://github.com/libguestfs/libguestfs/blob/16fdcb4baabcd96dcc16acf1ec7... In fact this canonicalization code was used so widely, I added it to the API in later versions: https://github.com/libguestfs/libguestfs/blob/99759da25c29a7376490074da3d... https://github.com/libguestfs/libguestfs/blob/faf548a4bdd36b476ee6838bfc7... For parameters, the mapping process is documented here: http://libguestfs.org/guestfs.3.html#algorithm-for-block-device-name-tran... The main reason for mapping parameters is so you can write guestfish scripts which are portable across many versions of libguestfs, eg: guestfish -a foo.img -m /dev/sda1 will just work. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://et.redhat.com/~rjones/virt-df/