Description of problem: For some reason this only happens with virt-alignment-scan, not with virt-df, even though both tools do roughly the same operations. $ sudo virt-df -d Win2003 Filesystem 1K-blocks Used Available Use% Win2003:/dev/sdb 638856 638856 0 100% Win2003:/dev/sda1 6281380 3405532 2875848 55% $ sudo virt-alignment-scan -d Win2003 /dev/sda1 32256 512 bad (alignment < 4K) libguestfs: error: part_list: could not parse row from output of parted print command: /dev/vdb:654188544B:virtblk:512:512:unknown:Virtio Block Device:; $ sudo virt-alignment-scan -d Win2003 -x libguestfs: trace: add_domain "Win2003" "readonly:true" "allowuuid:true" "readonlydisk:read" libguestfs: trace: add_domain = 2 libguestfs: trace: launch libguestfs: trace: launch = 0 libguestfs: trace: list_devices libguestfs: trace: list_devices = ["/dev/vda", "/dev/vdb"] libguestfs: trace: part_list "/dev/vda" libguestfs: trace: part_list = <struct guestfs_partition_list *> /dev/sda1 32256 512 bad (alignment < 4K) libguestfs: trace: part_list "/dev/vdb" libguestfs: trace: part_list = NULL (error) libguestfs: error: part_list: could not parse row from output of parted print command: /dev/vdb:654188544B:virtblk:512:512:unknown:Virtio Block Device:; libguestfs: trace: close libguestfs: trace: shutdown libguestfs: trace: internal_autosync libguestfs: trace: internal_autosync = 0 libguestfs: trace: shutdown = 0 Version-Release number of selected component (if applicable): libguestfs 1.18.5 How reproducible: 100% on a single Windows 2003 guest with two disks.
Same error in libguestfs 1.19.24.
OK, so this is parted stupidity, and a dupe of a bug we've already found and fixed in parted (but only in Rawhide). The output of the command is: # parted -m -- /dev/vdb unit b print Error: /dev/vdb: unrecognised disk label BYT; /dev/vdb:654188544B:virtblk:512:512:unknown:Virtio Block Device:; NB The error message is set to stdout. parted-3.0-10.fc17.x86_64 *** This bug has been marked as a duplicate of bug 745606 ***