Operating systems

3. Background: Some operating systems allow you to mount a file as a device, for example, Apple allows mounting disk image files (.dng suffix). This primarily used as a software distribution mechanism, but it has a wide variety of potential uses. For example, after an old computer fails, it is sometimes possible to copy the disk image of that system into a file in the file system on a new computer and then extract and rescue content from the old file system that might otherwise have been lost. When a disk image file is mounted under an operating system, the directory structure stored on the mounted disk image becomes available on an equal footing with the directory structures of real disks mounted on that system. a) Where does the disk scheduler go? Specifically, is there any need for a disk scheduler for the mounted disk image? Briefly, why or why not? (0.5 points) b) What if the natural block size (the sector size) of my real disk differs from the natural block size of my mounted disk image file. Would this be easier to deal with using the Unix read) and write kernel calls as a disk interface, or using the linearized sector number scheme outlined in the notes for Feb. 21? Briefly explain your answer. (0.5 points)