Description of problem: $ guestfish -N lvfs:/dev/VG/LV1 part-to-dev /dev/VG/LV1 /dev/VG/LV $ guestfish -N lvfs:/dev/VG/LV1 part-to-partnum /dev/VG/LV1 1 It's a bit harder to demonstrate from the command line, but the same thing happens with md paths (/dev/md0 -> /dev/md, 0) Version-Release number of selected component (if applicable): libguestfs-1.36.4-1.fc26.x86_64 but also happens upstream How reproducible: 100% Steps to Reproduce: 1. See above.