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

[carlopmart]

On 02/03/2011 06:08 PM, Phil Meyer wrote:
> 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!
>

Thanks Phil. I will run minimal services on host side (ntp, postfix and kvm). In the 
example that you explain, does enough with the host had, for example, 8.5 GB of RAM?

I don't need HA or Clustering services or to connect to external storage (I will use 
local disks).

Thanks.


-- 
CL Martinez
carlopmart {at} gmail {d0t} com