How to run a Sahara cluster on bare metal servers¶

Hadoop clusters are designed to store and analyze extremely large amounts of unstructured data in distributed computing environments. Sahara enables you to boot Hadoop clusters in both virtual and bare metal environments. When Booting Hadoop clusters with Sahara on bare metal servers, you benefit from the bare metal performance with self-service resource provisioning.

1. Create a new OpenStack environment using Devstack as described in the Devstack Guide
2. Install Ironic as described in the Ironic Installation Guide
3. Install Sahara as described in the Sahara Installation Guide
4. Build the Sahara image and prepare it for uploading to Glance:
   • Build an image for Sahara plugin with the -b flag. Use sahara image elements when building the image. See https://git.openstack.org/cgit/openstack/sahara-image-elements
   • Convert the qcow2 image format to the raw format. For example:

$ qemu-img convert -O raw image-converted.qcow image-converted-from-qcow2.raw

• Mount the raw image to the system.
• chroot to the mounted directory and remove the installed grub.
• Build grub2 from sources and install to /usr/sbin.
• In /etc/sysconfig/selinux, disable selinux SELINUX=disabled
• In the configuration file, set onboot=yes and BOOTPROTO=dhcp for every interface.
• Add the configuration files for all interfaces in the /etc/sysconfig/network-scripts directory.

5. Upload the Sahara disk image to Glance, and register it in the Sahara Image Registry. Referencing its separate kernel and initramfs images.
6. Configure the bare metal network for the Sahara cluster nodes:

• Add bare metal servers to your environment manually referencing their IPMI addresses (Ironic does not detect servers), for Ironic to manage the servers power and network. For example:

$ ironic node-create -d pxe_ipmitool \
  -i ipmi_address=$IP_ADDRESS \
  -i ipmi_username=$USERNAME \
  -i ipmi_password=$PASSWORD \
  -i pxe_deploy_kernel=$deploy.kernel.id \
  -i pxe_deploy_ramdisk=$deploy.ramfs.id

$ ironic port-create -n $NODE_ID -a "$MAC_eth1"

• Add the hardware information:

$ ironic node-update $NODE_ID add properties/cpus=$CPU \
  properties/memory_mb=$RAM properties/local_gb=$ROOT_GB \
  properties/cpu_arch='x86_64'

7. Add a special flavor for the bare metal instances with an arch meta parameter to match the virtual architecture of the server’s CPU with the metal one. For example:

$ nova flavor-create baremetal auto $RAM $DISK_GB $CPU
$ nova flavor-key baremetal set cpu_arch=x86_64