* Go to Virtual Machines * Select VM * Go to Disks tab * Select attached disk * Right-click -> "Scan Alignment" Got message : VDSM hyper01 command failed: An error scanning the disk image or guest: ['libguestfs: error: qemu-img: /tmp/libguestfs7aaw3Z/overlay1: qemu-img exited with error status 1.', 'To see full error messages you may need to enable debugging.', 'See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs'] rhevm-3.6.0-0.18.el6.noarch vdsm-4.17.8-1.el7ev.noarch Disk interface VirtIO Storage type iSCSI
*** This bug has been marked as a duplicate of bug 1151838 ***
It was a permission problem. The solution was: Create a new disk profile for storage domain and remove the old one.