Questions from Operating Systems

Q: In the traditional UNIX file access model, UNIX systems provide a

In the traditional UNIX file access model, UNIX systems provide a default setting for newly created files and directories, which the owner may later change. The default is typically full access for th...

Q: Consider user accounts on a system with a Web server configured to

Consider user accounts on a system with a Web server configured to provide access to user Web areas. In general, this scheme uses a standard directory name, such as , in a user’s home directory. This...

Q: For this problem, first consider the case where you wish to

For this problem, first consider the case where you wish to order pizza for a party of guests. The layer models in Figure 17.8 can be used to describe the ordering and delivery of a pizza. The guest e...

Q: List the major disadvantages of the layered approach to protocols.

List the major disadvantages of the layered approach to protocols.

Q: Figure 6.18 shows another solution to the dining philosophers problem

Figure 6.18 shows another solution to the dining philosophers problem using monitors. Compare to Figure 6.14 and report your conclusions. Figure 6.18: Figure 6.14:

Q: A TCP segment consisting of 1,500 bits of data and

A TCP segment consisting of 1,500 bits of data and 160 bits of header is sent to the IP layer, which appends another 160 bits of header. This is then transmitted through two networks, each of which us...

Q: Let be the percentage of program code that can be executed simultaneously

Let be the percentage of program code that can be executed simultaneously by n computers in a cluster, each computer using a different set of parameters or initial conditions. α Assume the remaining c...

Q: An application program is executed on a nine-computer cluster.

An application program is executed on a nine-computer cluster. A benchmark program takes time T on this cluster. Further, 25% of T is time in which the application is running simultaneously on all nin...

Q: The following FORTRAN program is to be executed on a computer,

The following FORTRAN program is to be executed on a computer, and a parallel version is to be executed on a 32- b computer cluster: L1: DO 10 I=1,1024 L2: SUM(I)=0 L3: DO 20 J=1, I L4: 20 SUM(I)=SUM(...

Q: Why does the TCP header have a header length field while the

Why does the TCP header have a header length field while the UDP header does not?