[rhelv6-list] Minimal RAM for a RHEL6 KVM host?

[Phil Meyer]

On 02/03/2011 09:00 AM, carlopmart wrote:
> Hi all,
>
>  Which is the minmal amount of RAM needed for a RHEL6 KVM host?? I 
> read RedHat's docs about this, and it seems 2GB ... Really??
>
>  Is it possible to limit RAM used by the KVM host as a Xen does??
>
>  Thanks.

Xen dom0 is a tiny, raw hypervisor using bits of the Linux kernel to 
operate hardware.

KVM is a kernel module based hypervisor.  Thus it uses the full kernel 
and OS with all that implies.

VMs utilizing the KVM hypervisor run as applications in the host 
application space.  This is totally different than Xen.

It has great advantages, and a few disadvantages.

Using KVM, you have to think of the VMs as fixed sized applications.

Want to run 2 4GB KVM VMs?  The host needs to have more than 8GB 
available to it in order to dedicate RAM to the VMs as well as manage 
its own resources.

I am bending the specifics slightly to make the point that KVM based VMs 
run on top of a full kernel/OS, and that KVM VMs are treated as 
applications within that space.

Hope this helps.

Good Luck!