instack-undercloud/doc/source/virt-setup.rst

Virtual Environment Setup

instack-undercloud can be deployed in a virtual environment using virtual machines instead of actual baremetal. One baremetal machine is still needed to act as the host for the virtual machines.

instack-undercloud contains the necessary tooling to create and configure the environment.

Minimum System Requirements

This setup creates 5 virtual machines consisting of 4GB of memory and 40GB of disk space on each. The virtual machine disk files are thinly provisioned and will not take up the full 40GB initially.

The minimum system requirements for the virtual host machine are:

• A baremetal machine with virtualization hardware extenstions enabled. Nested KVM is not supported.
• At least (1) quad core CPU
• 12GB free memory
• 120GB disk space¹

If you want to increase the scaling of one or more overcloud nodes, you will need to ensure you have enough memory and disk space.

Preparing the Host Machine

1. Install RHEL 7.1 Server x86_64 or CentOS 7 x86_64.

2. Make sure sshd service is installed and running.

3. The user performing all of the installation steps on the virt host needs to have sudo enabled. You can use an existing user or use the following commands to create a new user called stack with password-less sudo enabled. Do not run the rest of the steps in this guide as root.

   • Example commands to create a user:

     sudo useradd stack
     sudo passwd stack  # specify a password
     echo "stack ALL=(root) NOPASSWD:ALL" | sudo tee -a /etc/sudoers.d/stack
     sudo chmod 0440 /etc/sudoers.d/stack

4. Make sure you are logged in as the non-root user you intend to use.

5. Download and execute the instack-undercloud setup script:

   curl https://raw.githubusercontent.com/rdo-management/instack-undercloud/master/scripts/instack-setup-host | bash -x

6. Install instack-undercloud:

   sudo yum install -y instack-undercloud

7. The virt setup automatically sets up a vm for the Undercloud installed with the same base OS as the host. See the Note below to choose a different OS.:

Note

To setup the undercloud vm with a base OS different from the host, set the $NODE_DIST environment variable prior to running instack-virt-setup:

# To choose CentOS 7:

export NODE_DIST=centos7 # To choose RHEL 7.1: export NODE_DIST=rhel7

8. Run the script to setup your virtual environment.:

Note

If building a RHEL 7.1 undercloud, download the RHEL 7.1 cloud image or copy it over from a different location, and define the needed environment variables for RHEL 7.1 prior to running instack-virt-setup:

curl -O http://download.devel.redhat.com/brewroot/packages/rhel-guest-image/7.1/20150203.1/images/rhel-guest-image-7.1-20150203.1.x86_64.qcow2 export DIB_LOCAL_IMAGE=rhel-guest-image-7.1-20150203.1.x86_64.qcow2 export DIB_YUM_REPO_CONF=/etc/yum.repos.d/rhos-release-6-rhel-7.1.repo

instack-virt-setup

When the script has completed successfully it will output the IP address of the instack vm that has now been installed with a base OS.

Running sudo virsh list --all² will show you now have one virtual machine called instack and 4 called baremetal[0-3].

You can ssh to the instack vm as the root user:

ssh root@<instack-vm-ip>

The vm contains a stack user to be used for installing the undercloud. You can su - stack to switch to the stack user account.

Continue with Installing the Undercloud

Footnotes

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1. Note that some default partitioning scheme will most likely not provide enough space to the partition containing the default path for libvirt image storage (/var/lib/libvirt/images). The easiest fix is to customize the partition layout at the time of install to provide at least 200 GB of space for that path.↩︎

2. The libvirt virtual machines have been defined under the system instance (qemu:///system). The user account executing these instructions gets added to the libvirtd group which grants passwordless access to the system instance. It does however require logging into a new shell (or desktop environment session if wanting to use virt-manager) before this change will be fully applied. To avoid having to re-login, you can use sudo virsh.↩︎