I have installed a 32 bit RHEL OS on a 64 bit system.
From the wiki page of PAE:
The Linux kernel includes full PAE mode support starting with version 2.3.23, with Linus Torvalds mentioning PAE's 4 MB page support in 1.3.15,[18] enabling access of up to 64 GB of memory on 32-bit machines.
The current kernel version in one of the server is:
2.6.32-431.17.1.el6.i686
Question 1
Does the kernel version mean that if I add another 24 GB RAM to my already existing 8 GB RAM, the entire 32 GB physical memory will become usable?
Currently the system shows that 8 GB RAM is available (I use free
command to check it).
Question 2
I am still confused on the virtual memory concepts.
How will the 32 bit system use the virtual memory?
I read that 32 bit RHEL will use the memory in chunks of 3 GB.
Does this mean, at any point of time, there can be only maximum 3 GB in the main memory?
I thought since I have 32 GB memory at any time 32 GB data can reside in main memory. Particularly, I am trying to understand the answer from here:
Each process runs in its own address space, and being 32-bit restricts that address space to about 3GB for each process. The sum of the memory used by 32-bit applications is completely irrelevant. There is nothing to get around.