pae kernel with xen

vp0619520 · 05-26-2012, 02:37 AM

Hi all,
I have Mint in my laptop,and it has 4G memory.I just install the PAE kernel.The OS is running normally.I can see the memory is totally distinguished by using command "free".Then I install the xen-hypervisor and reboot the computer.I can see the DOM0 with the command "xm",below is the output:

Code:

xm list
Name                                        ID   Mem VCPUs      State   Time(s)
Domain-0                                     0  3066     2     r-----    154.5

But I also found that there are only about 3G RAM distinguished by the kernel.

Code:

free -m
             total       used       free     shared    buffers     cached
Mem:          2926        955       1971          0        111        401
-/+ buffers/cache:        442       2483
Swap:         3906          0       3906

The kernel running now is

Code:

uname -r
3.2.0-24-generic-pae

Can anyone tell me how did it come to this?Do I need to change the system to 64bit for using more than 4G RAM in the xen kernel? Thanks a lot!

vp0619520 · 05-29-2012, 04:09 AM

Hi all,
I have change the OS to the 64bit version.And I install the xen-hypervisor,then I boot from this kernel.It seems the memory is still can not be
fully distinguished .

blue_print · 05-29-2012, 07:12 AM

Install ListHardware package and see if the system has 4GB RAM physically.

Code:

yum install lshw (RHEL/CENTOS/FEDORA)
apt-get install lshw (Ubutu/Debian)

To check the memory

Code:

lshw | grep 'bank' -A10

chrism01 · 05-29-2012, 07:11 PM

32 Bit SW can only use max of 4GB (in fact more like 3.5-3.7 due to some overhead).
Changing the OS to 64 bit isn't going to help if you've only got 4GB of physical RAM... in fact even then you'd need 64 bit SW to be able to make use of more RAM for that process.

vp0619520 · 05-29-2012, 08:06 PM

Quote:

Originally Posted by chrism01

32 Bit SW can only use max of 4GB (in fact more like 3.5-3.7 due to some overhead).
Changing the OS to 64 bit isn't going to help if you've only got 4GB of physical RAM... in fact even then you'd need 64 bit SW to be able to make use of more RAM for that process.

Sorry,what's the meaning of "SW"?

chrism01 · 05-30-2012, 06:48 PM

SW = software HW = hardware OS = Operating System

vp0619520 · 05-30-2012, 08:10 PM

Quote:

Originally Posted by chrism01

SW = software HW = hardware OS = Operating System

Thanks, I just installed the xen-hypervisor for amd64.But it seems there is no affection.