Processes and Data Management

Question 1

Linux package characteristics

Answer 1

1. Is a single file
2. Rely on other programs to instal the software
3. Contain dependency information
4. Contain version information
5. Contain architecture information
6. Binary packages are built from source packages

Question 2

Process of package installation

Answer 2

1. Command issued to install program
2. Software locate all dependencies
3. User issues final approval
4. Software downloads all dependency packages
5. Software installs the packages

Question 3

/sbin/init

Answer 3

• Initialize process
• runs when starting OS
• Programs launched by init are Children

Question 4

Parent

Answer 4

process that launched a program

Question 5

Child

Answer 5

process launched by another program

Question 6

Process ID (PID)

Answer 6

• Begin with 1
• Unique ID point to a program
• Init process ID is 1

Question 7

Parent Process ID (PPID)

Answer 7

• Points back to a parent
• Process ID of Parent process
• Process launched by init would be 1

Question 8

ps command

Answer 8

• Displays a process listing
• Pipe thorough grep to filter/query
• Provides information at a single point in time only

Question 9

top command

Answer 9

• Displays an interactive process listing
• Sorts by CPU usage like task manager
• Gives load average (how much resources process usually uses)
• M key to sort by memory

Question 10

free command

Answer 10

• return total memory status
• Mem & Swap are improtant fields

Question 11

Memory leak

Answer 11

• Bug where program consumes increasing amounts of memory, failing to return after requesting RAM.

Question 12

Mem

Answer 12

• Line in free command output that reveals total RAM statistics
• Buffer/cache line, shows the amount of memory being actively used at current time

Question 13

Swap

Answer 13

• Line in free command output that reveals how much swap space Linux is using
• Disk space that’s set aside as an adjunct to memory (virtual RAM)

Question 14

Kernel Ring Buffer

Answer 14

• Like a log file for the kernel itself
• Stored in memory rather than disk file
• dmesg to display info pipe less to display less, or grep to search
• Useful for troubleshooting hardware and driver problems

Question 15

Package software

Answer 15

• Maintains a DB about installed packages

Question 16

Daemons

Answer 16

• Programs that run in the background