Comp111 - Quiz 2 Review 4

Dec 8, 2009 - closed book

Name:________________________________

Login:______________

Please fill in the blanks. Each blank is worth 5 points. Blanks with the same number have the same answer.

  1. The exponential distribution is ________1________ , i.e., the time taken by one request is ________2________ from the times for previous requests.
  2. In segmented memory addressing, a memory address is treated as containing three sub-addresses describing the ________3________, ________4_________ and ________5________ of the memory location. Segments are utilized in order to group pages that should share the same ________6________; this saves ________7________ that would otherwise be needed to store this information for each page or word.
  3. When one opens a file, the ________8________ gets a descriptor that points to a ________9________ that is shared by any processes that happen to open the file.
  4. Every UNIX file has a corresponding ________10________ that contains information on the file's location, ________11________, group, and protections.
  5. If the power fails unexpectedly on a filesystem, then a specific block might be simultaneously inside a file and on the ________12________ list. This is because blocks are written to the physical disk as ________13________ as possible.
  6. Writing a byte to disk is a complicated procedure. First the ________14________ containing the byte is read into memory, modified, and marked as ________15________. At some later time, all ________15________ pages are flushed to disk. In a journalling filesystem, these are stored as ________16________ in a special part of the disk.
  7. A device ________17________ is a program that controls a physical or pseudo device. The ________18________ number of a device identifies the driver, while the ________19________ number identifies the specific device or options.
  8. One of the things that makes I/O subsystems difficult to understand is that they are composed from producer-consumer relationships at different scales. The ________20________ requires information in a specific format and in chunks it can manage, while the application provides that information in different-size chunks.