architecting your data center (version 2) - part 1 - the kvm server

this is the 2nd part of series i am writing about architecting your data center (version 2)

so after a bit of experimentation, i have come to the conclusion that the first step is NOT to setup the rdo-manager's undercloud but in fact to
set up a KVM host. the logic being with a kvm host i can set up a VM for the rdo-manager's undercloud, take snapshots and restore to a previous snapshot if a mistake or 2 is made.

this basically means

a) i will need 3 physical machines to hosts instances

• 1 kvm host
• 2 for the overcloud (no ceph)

b) all the software that i will be installing will be VMs on the KVM host

installation

there is nothing unfamiliar with the kvm host. a minimal centos7 installation was carried out after i verified that the physical box could support virtualisation. to verify my cpu did support virtualisation i used my trust script located on github

i did install a few applications after the minimum server configuration was installed.

yum -y install qemu-kvm qemu-img virt-manager libvirt libvirt-python libvirt-client virt-install virt-viewer bridge-utils tunctl urw-fonts xorg-x11-xauth

then after that I needed to create a bridged interface to provide to the VMs. with a bridged interface i can connect directly from my laptop as the VM will have a real ip as opposed to a virbr0 interface that gives out an ip from a dhcp in the 192.168.122.0/24 network

the following is what i ended up with

/etc/sysconfig/network-scripts/ifcfg-br0

    DEVICE=br0
    TYPE=Bridge
    BOOTRPOTO=static
    ONBOOT=yes
    IPADDR0="192.168.0.249"
    PREFIX0="24"
    GATEWAY0="192.168.0.1"
    DNS1="8.8.8.8"
    DNS2="4.2.2.2"

and

/etc/sysconfig/network-scripts/ifcfg-eth0

    TYPE=Ethernet
    BOOTPROTO=none
    NAME=eth0
    UUID=ab7ac142-1bb0-40de-b778-c1a17c4ee192
    DEVICE=eth0
    ONBOOT=yes
    BRIDGE=br0

of course, that does come up with a lovely situation where there is no redundancy. i have been thinking about it and maybe the solution is ovirt and believe me the irony of it is not lost on me.

anyways, the next step is to "perfect" a minimal centos7 install on a vm that i can use as a template to clone from.

stay tuned!