1. Consider demand paging. You are given the following reference string, page replacement policy and the number of frames available. Calculate the number of page faults in each case. A. ReferenceString:1234234235672342310 989108123 Algorithm: LRU
# of frames: 3
B. Reference String: Algorithm: Optimal
# of frames: 3
C. Reference String: Algorithm: LRU
# of frames: 2
D. Referencestring:1237841241541241281 011324171011 Algorithm: FIFO
# of frames: 3
E. Referencestring:1237841241541241281 011324171011 Algorithm: FIFO
# of frames: 4
To answer the question, write down the # of page fault, and also copy the reference string and circle all references that causes a page fault.
2. For the disk scheduling algorithm such as SCAN/c-SCAN, rotational delays are not used for optimization purpose. Suppose time require for one rotation is nearly the same as time to travel one track during seeking, suggest a way that you can further optimize one of the above algorithms.
3. For main memory allocation, nowadays virtually all systems uses demand paging, not contiguous allocation. However, for space allocation for files, contiguous allocation is still being used. Suggest two reasons why.

What is the first step in creating a maintenance ?

Ihave a music player on my phone. i can buy songs, add them to playlists and play them. obviously it would be redundant to store each song in each playlist; each playlist is just a list of pointers to the songs. for this lab you will simulate this behavior. your program will need to have options to: add songs to the system library (you will store the text of the first line of the song, rather than the audio) add playlists add songs to a playlist list playlists play a playlist list all of the songs in the library with a count of how many times each song has been played remove a song from a playlist remove a playlist remove a song from the library (and thus from all playlists that contain it) note that we will not be checking many error cases. in real programming this would be bad, you should usually try to recognize and respond to as many types of errors as you can. in the context of class we are trying to acquaint you with as many concepts as possible, so for the sake of educational efficiency we will not be checking most errors in this lab, you may assume that your user provides correct input. you may add all appropriate error testing if you wish, but we will not be testing for it.

Drag each label to the correct location on the image list the do’s and don’ts of safeguarding your password. a. keep yourself logged in when you leave your computer.b. don’t write your password down and leave it where others can find it.c. share your password with your friends.d.each time you visit a website,retain the cookies on your computer.e. use a long password with mixed characters.1. do's 2. don'ts