search for: sdzzz

...a <- your normal drives /dev/sdb <- [/dev/sdc # sorry, you can't use this, we won't tell you why] /dev/sdd <- your first hotplugged device As far as I know, the kernel assigns /dev/sdX names on a first-free basis, so there's no way to permanently put the appliance at /dev/sdzzz (if there is, please let me know!) (2) The "slots" option In this option you'd have to use null devices to reserve the maximum number of drive slots that you're going to use in the libguestfs handle before launch. Then after launching you'd be allowed to hotplug only those...