100 reads,101 writes, to shift blocks down by one linked 1 write of new block pointing to old beginning of file indexed 1 write of new block b. 11.10 Ramdisk is useful in cases where an application needs to access a filesystem like structure very quickly. It is also a good way of maintaining data at the speed of memory cache without the possibility that it will be replaced by other data. Also, in the event that all of the secondary storage is undergoing a reformat, a RAM disk would provide a temporary file system on which the OS can still run.
Times are longer.
Yes, because it significantly improves disk access time. Streams of different disk access locations can occur in any kind of user enviroment, and the same speed up benefits would apply. 13.11 Rotational latency is usually not an issue because it is a near constant factor, it pales in comparison to seek latency, and many drives read and write entire cylinders at a time, so the access granularity is at a rougher level. It's difficult to determine which part of the disk will be under the head after a seek, so you can't really SSTF across cylinders to determine which portion of the track is closest. SCAN would be modified to scan each individual track entirely before moving on to the next cyl.