1.2.3 Virtual Memory

Question 1

Running out of Memory

Answer 1

Virtual Memory
Terminating processes
Installing more RAM

Question 2

Virtual memory

Answer 2

Use secondary storage as if it were RAM.

Can have negative impacts on performance.

Can have negative impacts on the health of SSDs

Might have limited space in secondary storage

Question 3

Terminating processes

Answer 3

By closing some processes that we are not using, we can free the memory that they are using.

This is not always possible because we may need all the processes.

Question 4

Installing more RAM

Answer 4

Store more data.

Not ideal as it can be expensive and we may only need more memory on a temporary basis.

Question 5

How Virtual Memory Works

Answer 5

Allows us to access more memory than we have by setting aside some secondary storage space to act as extra memory.

Question 6

Paging

Answer 6

Memory can be split into pages.

Works by moving these pages between the RAM and secondary storage.

Question 7

Move pages to HDD

Answer 7

If a page is not being used, then we might want to put it into Virtual Memory.

When a page is moved to the HDD, it is put into a special file called the pagefile.

Other processes can then use the memory that we just freed in the RAM.

Question 8

Move pages to RAM

Answer 8

When we want to use a page again, we first need to move it back to the RAM.

We do this by swapping the page that we want with one that is already in the RAM.