CSCI 4500/8506 Page 1 Module 11 Practice QuestionsCSCI 4500/8506 – Spring 2012Additional Sample Questions for Final Examination(covers module 11)1. With respect to memory in a computer system, the term persistent meansa. the feature of the device to force data to be written evenly across the available memoryblocks, thus preventing one area of memory from becoming more 'worn' and failingfaster.b. the ability of a memory type to retain its contents even after its power source has beenremoved.c. the necessity of the interface between the memory and the system bus to maintain thedata on the bus for a specified period of time if it is to be written reliably.2. Assume a disk device can be read by a user application, and further assume that this diskcontains files belonging to many users. What prevents the user application from reading filesbelonging to other users?a. The disk device driver, which knows the ownership of each disk block and preventsaccess to those not belonging to the user owning the application process.b. Nothing, since the individual disk blocks containing files and other information can beread without any security checks.c. None of the other answer choices is correct.3. Many storage devices used by filesystems in modern computer systems are removable, likefloppy disks, CDs and DVDs, and flash RAM. Why is it usually necessary to inform theoperating system before physically removing one of these devices from the system?a. It is not necessary to do this, since the system will automatically record information thatis to be written to the device while it is removed, and then later write it to the devicewhen it is again connected to the system.b. The operating system usually buffers data (in RAM) that is to be written to removabledevices, so the writing is not necessarily complete as soon as a write or close system callis completed. Telling the system you want to remove the device tells it to write allmodified data in buffers to the device before indicating it is safe to remove the device.c. None of the other answer choices is correct.4. Suppose multiple distinct file systems are stored on a single physical disk. The storageregion in which each of these file systems is located is usually called a ________ .a. partitionb. segmentc. sector5. In a file system, the unit of information to which protection is applied is called a ______ .a. protection unitb. sectorc. fileCSCI 4500/8506 Page 2 Module 11 Practice Questions6. The extension -- the part of a file name that usually appears at the end of a file name after aperiod -- usually indicates _____ .a. the type of information contained in the file.b. the protection associated with the file.c. which version, or generation, of the information this particular file represents.7. Obviously applications depend on the content of files conforming to certain expectations. Isthe structure of a file's content imposed by the operating system? And if so, why?a. No, arbitrary files may contain any structure desired by the user.b. No, as long as the application only uses the standard system calls to write information toa file.c. It depends on the operating system and the file type whether any particular structure isimposed.8. In UNIX systems, regular files contain _____ .a. well-known structured information, like directoriesb. user information that has a regular structure in each record (for example, text files inwhich all lines have the same length)c. user information (text files, source code, data and executable programs)9. A keyed file is one which _____ .a. each record has a unique identifier that can be used in search operationsb. each access is recorded in a log file which has records containing a pair of fields, key andfilenamec. None of the other answer choices is correct.10. In UNIX, a character special file isa. a file which, when accessed, results in input/output operations on a device which isaccessed one byte at a time.b. a file that contains a single character such that any access triggers special security actionsby the system.c. None of the other answers is correct.11. Suppose a UNIX file has multiple names (that is, multiple physical links). When is the file'scontent actually deleted?a. When each of the links to the file has been deleted.b. When any of the links to the file are deleted.c. None of the other answer choices is correct.12. What are the principal purposes of the open system call?a. return a unique descriptor which is then used in other calls to access the open fileb. verify the file existsc. All of the other answers are correct.CSCI 4500/8506 Page 3 Module 11 Practice Questions13. In most systems (certainly in UNIX), all files opened by a process are closed when theprocess terminates. Why, then, is there a separate system call that allows a user to explicitlyclose a file?a. If the process wants to open the same file a second (or later) time with different accesspermissions (perhaps to write the file, when the first open was for read only), then thefirst open instance of the file must be closed.b. A child process usually inherits open files from its parent, and the close system call isprovided to allow child processes to close these inherited instances.c. Open files consume system resources, and there is a limit on the number of files aprocess may have open at the same time. Thus closing a file frees resources and allowsadditional files to be opened.14. When a UNIX file is open, there is a unique position associated with the file that indicateswhere the next read or write operation will commence. A system call is provided that allowsa process to arbitrarily change this position. That system call is named _____ .a. lseekb. positionc. goto15. When a UNIX file is open, there is a unique position associated with the file that indicateswhere the next read or write operation will commence. After a read or write, how is thatposition altered?a. It is incremented by the number of bytes read or written.b. It is incremented by the size of a logical block on the filesystem (usually a power of 2).c. None of the other answer choices is correct.16. A directory (sometimes called a folder) contains information about a collection of files. InUNIX systems the entries in a directory contain a file's name and _____ .a. the number of an i-node.b. the location of the first block of the file.c. all of the other information in the other answer choices.17. The size of a file is an important file attribute. In the CP/M operating system, what