Hi,

On a 4gb 64 bit centos kvm guest per libvirt

<memory>4194304</memory> <currentMemory>4194304</currentMemory>

but in dmesg of the guest I find

Memory: 4039712k/5242880k available (2592k kernel code, 154076k reserved, 1653k data, 224k init)

Why is dmesg reporting 5g of ram ? Or am I reading wrong ? How much memory on the Host is necessary on the kvm host for this "4g" machine in the worst case (I try to not overcommit for now). I want to avoid the situation that this "4g" machine requires "5g".

A 4gb 32 bit machine is reporting expected values

Memory: 3102712k/4194304k available (2190k kernel code, 41592k reserved, 911k data, 228k init, 2228160k highmem)

All of the above lead to the following more generic question: How many percent of the Host RAM may I safely give to guests (without overcommiting) ?