Suppose a disk has 201 cylinders, numbered from 0 to 200. At some time the disk arm is at cylinder 100, and there is a queue of disk access requests for cylinders 30, 85, 90, 100, 105, 110, 135 and 145. If Shortest-Seek Time First (SSTF) is being used for scheduling the disk access, the request for cylinder 90 is serviced after servicing ____________ number of requests.

A FAT (file allocation table) based file system is being used and the total overhead of each entry in the FAT is $$4$$ bytes in size. Given a $$100\,\, \times \,\,{10^6}$$ bytes disk on which the file system is stored and data block size is $${10^3}$$ bytes, the maximum size of a file that can be stored on this disk in units of $${10^6}$$ bytes is __________.

The data blocks of a very large file in the Unix file system are allocated using

Consider a disk pack with 16 surfaces, 128 tracks per surface and 256 sectors per track. 512 bytes of data are stored in a bit serial manner in a sector. The capacity of the disk pack and the number of bits required to specify a particular sector in the disk are respectively: