1. The OS controls an I/O device by a) sending a message to the devices port, b) using CPU instructions specific to that device, or c) writing to registers in the devices controller.

2. Which of the following is not a way for for the OS to interact with an I/O device: a) DMA, b) programmed I/O, c) handling I/O interrupts, or d) a data link protocol

3. A disk drive has a speed of 12000 RPM, an average seek time of 5 ms, and a transfer rate of 140 MB/sec. How much time does it take to perform 50 random reads of 10 KB? (In other words, the 50 reads are from random spots on the drive, but each individual read is performed sequentially.) Give your answer in units of seconds.

4. Given the same information as in c) above, what is the I/O rate for the 50 reads? Give your answer in MB/sec.

5. When a Linux directory is first created, how many entries does it contain? a) 0 b) 1 c) 2 d) 16

6. On hosting, what type of file system is /home/CLASSES? a) ext3, b) ext4, c) tempfs (hint: when a volume is mounted, the file system type is given. See the mount man page.)