[Autogenerated] this brings us to the concept of page files.
What is a page file anyway.
The basic idea is that when we're using memory,
if we don't have any kind of page file,
we can only use the RAM that we have once RAM is exhausted.
That's it.
We're out.
There is no more memory.
We can commit.
So the purpose of a page file or page files is to provide more
storage for writeable private committed memory.
Let's make sure we understand these terms here.
So first we're talking about committed memory only,
obviously because if the memory is reserved,
then there's nothing there, there's nothing to back up.
It has to be committed memory.
It's about private memory because shared memory is typically
backed up by a file that already exists.
For example,
if using some DLL and you didn't use that DLL for a
little while in your process.
And so the manager might have to might have decided to
throw these pages outside of RAM,
but there's no need to write them to a page file
because the DLL is its own backup.
And this is one reason when you try to delete the realities in use,
it won't work because it's being mapped,
it's actually being used and we discussed memory mapped files to
some extent in the last module of discourse,
but just know that when we're talking about this shared stuff,
there's no need to use a page file,
it's only for private memory and something which of course is
writeable otherwise we can't really change that anyway.
And so in terms of page files Windows supports up to 16 page files,
not just one.
Typically you have one when you're just installing
Windows but you can have more up to 16.
Only two unarmed by the way on other architectural support,
16 there must be on different partitions.
They're always named page file dot CS in the root partition of the disk you
can set the initial size and the maximum size using the UI or the registry
which will demonstrate in the next demo in general.
Like most things in Windows,
page file information is stored in the registry and this is the
location in the registry where this is stored.
Notice it's a it's a local machine kind of thing.
And for every entry there you see the name of a drive like c colon and
then two numbers indicating the minimum the initial size and the
maximum size of that page file for that drive.
If you see both zeros,
it means that you're letting the system decide the size as the
system sees fit and I'll discuss that very soon.
The maximum size of a page file currently 16 terabytes
in all architectures except arm.
So it's fairly big.
So you can have multiple of these files up to 16 of those.
Each one on a different partition.
Let's see what that looks like on a typical system.
Mhm