Installation guide

Dell Inc.
KVM Virtualization in RHEL 6 Made Easy
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2. Preparing your environment
2.1 Hardware
You don‟t need a top-of-the-line PowerEdge server, a 2-socket server (with 4-6 cores each), 8-16 GB of
memory and 100 GB disk space is sufficient for 4 to 8 VMs, but of course it will depend on your needs.
In my lab I have a PowerEdge T610 with 2 Intel Xeon 4-core 5520 processors, 16 GB of memory and
about 160GB disk space and I can easily run 8-10 RHEL VMs without a sweat. Most of my VMs use 1 GB
of memory, 1 virtual CPU (VCPU) and around 15 GB of disk space.
One awesome feature in KVM is the concept of overcommitting, which allows you to allocate more
virtualized CPUs and memory than available resources on the host. The VMs then only use what they
need, allowing other VMs to use unused resources. So when you are planning your VM resources,
remember that you can allocate more resources than you actually have, but of course be mindful that
the total amount of resources actually being used by all VMs can‟t exceed the total amount of
resources available on your host.
2.2 Virtualization Technology
Verify that Virtualization Technology (VT) is enabled in your server‟s BIOS. Reboot your server and
press F2 during POST to go into the BIOS, the select “Processors Settings”, and verify “Virtualization
Technology” is “Enabled”. Save and Exit and let the server boot up.
Another thing to check once your server boots up is whether your processors support VT. This is
apparently not a requirement but it will help a lot with performance, you might be better off with
processors that do support VT. Check for these CPU extensions:
# grep -E 'svm|vmx' /proc/cpuinfo
- vmx is for Intel processors
- svm is for AMD processors
2.3 Required RPMs
There are several RPMs to install that are not part of the base RHEL 6 installation. Assuming that you
have a yum repository, install the following:
# yum install kvm python-virtinst libvirt libvirt-python virt-manager \
virt-viewer libguestfs-tools
Verify the following kernel modules are loaded, and if not load manually:
kvm
kvm_intel (only on Intel-based systems)