Dear Friends ,

I have to read the below doc and get the few idea (but not clear idea) regarding the difference between ramfs,tmpfs and swap .

I have some below technical question regarding the above memory areas :

1) what will be the memory usage flow for an OS ? For example , when a system is started and give some load then which order it maintain for memory utilization , like tmpfs-->ramfs-->swap ?

2) As per doc, I understand that , both tmpfs and ramfs takes space from physical memory directly . In this case , please see the below output :

>>
----------------------------------------------------------------------
[root@STAN ~]# df -H /dev/shm/
Filesystem Size Used Avail Use% Mounted on
tmpfs 34G 40M 34G 1% /dev/shm



[root@STAN ~]# free -m
total used free shared buffers cached
Mem: 64449 64277 172 0 305 61475
-/+ buffers/cache: 2496 61952
Swap: 131069 22 131046
---------------------------------------------------------


In the above scenario , Total physical RAM is 64G and tmpfs 34G .As per doc ,If this 34G RAM takes from Physical RAM , then Physical RAM should be (64+38)=102 G. But here my physical RAM is 64 G.
Then from where the 'tmpfs' takes his space ?

3) In the above example, which is the ramfs value ? Both ramfs and tmpfs used together in an Unix OS ?


Waiting for kind rely ...

Is this homework?

If you where to take that question and plug it into Google, or similar search engine you'd find this,
among other great ideas on how to do this and what it is about.

https://en.wikipedia.org/wiki/Tmpfs

Also notice the term "fs === file system."

This in contrast to "swap," which is low-level storage used by the virtual memory manager and which might either be a partition or a file.