Question

Hello, please answer all 3 questions, if possible! :) I will make sure to add 5 star rating!

29. Which of the following commands may be used to display boot error messages? (Choose all that apply.)

a. dmesg | less
b. less /var/log/boot
c. less /var/log/wtmp
d. less /var/log/boot.log

31. Which of the following can be used to obtain detailed performance statistics regarding virtual memory usage? (Choose all that apply.)

a. Files stored within the /proc directory.

b. The iostat command.
c. The vmstat command.
d. The sar command.

32. Which of the following commands can be used to tune system parameters that are stored within the /proc directory?

a. sysctl

b. iostat
c. sar
d. hdparm

Answer 1

Explanation:

29.

a. dmesg | less

d. less /var/log/boot.log

31.

a. Files stored within the /proc directory.

c. The vmstat command.

d. The sar command.

32.

a. sysctl

explanation:-

29.

• dmesg displays all the messages related to kernel. This will display the latest message with respect to kernel data. If we want to analyse the complete data, dmesg|less is used that will display page wise logs.
• less /var/log/boot.log contains the messages and boot info. If any error occurs, it can be found in the file.
• Option C is incorrect as the file is used for storing the last logged in data for the users.
• Option B is incorrect as it does not include an extension of a file.

31.

• The Vmstat command is used to give the virtual memory statistics with a interval of time. It is used as vmstat n, where n is the interval in seconds between the reports.
• sar command is another command that provides the data about system activity and generates the automatic report that provides the data.
• the files stored in /proc contain the hierarchy of virtual folders which helps in representing the state of the kernel. Thus, can be used for monitoring performance.
• Option B is incorrect as the isostat command is used to monitor the load of I/O devices and not memory.

32.

• sysctl command is used to set , view and automate the kernel settings and maintain the parameters that are available in /proc directory.
• Other options are incorrect as iostat command is used to monitor the load for I/O devices, whereas sar command is used to monitor the performance of virtual memory and hdparm is used for disk devices.