in an attempt to access a truecrypt container, I stumbled about the prerequisite of setting up a loop device...ncoghlan suggested in an earlier answerWhen you run it as root, losetup -f will automatically create loop devices as needed if there aren't any free ones available.  So rather than doing it yourself with mknod, the easiest way to create a new loop device is with sudo losetup -f. That approach will give you a free existing loop device if one exists, or automatically create a new one if needed.My result of sudo losetup f islosetup: f: failed to use device: No such file or directorySearching for this message+losetup so far does not help.Result of lsmod |grep loop isloop                   28672  0uname -r4.5.7-200.fc23.x86_64
how to add a loop device on fedora 23 with losetup?
linux;fedora;mount;encryption;loop device
Serge's comment made me do my homework - study the man page in more depth than before. The solution was simply to enter in the shelllosetup(without any arguments). Then, afterwards,losetup -fresulted, successfully, in/dev/loop0