December 17, 2020

St. Louis, MO

The soon to be released Orabuntu-LXC version 7.0.0-beta AMIDE for the first time offers fully-automated support for both LXC "spans across multiple hosts" and LXD true clusters, while continuing the existing support for LXC container networks spanned over multiple hosts.  Previous to this release, Orabuntu-LXC only supported LXC containers, but now LXD and LXD clusters are also supported (on Ubuntu 20.04 and Oracle Linux 8 only at the moment, other distros to be added soon). The OpenvSwitch networking has been re-designed, preserving all of the good features used with LXC containers, but also opening up the OpenvSwitch network to be "LXD-friendly."  The VLAN structure of Orabuntu-LXC has been preserved.

This guide details how to deploy an N-node LXD Cluster of hosts almost entirely automated except for preparing the hosts and creating the ZFS storage pool.  The guide uses the "to-lxd" branch at the Orabuntu-LXC github for building this demonstration N-node LXD cluster.  This tutorial is a 2-node cluster using GRE over OpenvSwitch as the cluster connection, but the guide can be generalized to N-Node by adding additional GRE nodes.

Figure 1.2 Using ifconfig to check the ip address of the VM.

Once the Ubuntu 20.04 HUB HOST server has been built, login to a terminal session, and begin the configuration of the server for Orabuntu-LXC install as shown below.

Shutdown the VM in preparation for adding two 25Gb LUNs for the ZFS storage pool for the LXD cluster.

Figure 2.1

Figure 2.2

Figure 2.3

Figure 2.4

Figure 2.5

Figure 2.6

Figure 2.7 Details of /dev/sdb sizing and dynamic allocation rather than fixed allocation.  Fixed allocation can be used if preferred.

Figure 2.8 Details of the /dev/sdc LUN.

Prepare the network settings as shown below. 

Figure 3.1 Details of the networking for the HUB HOST.  Note in particular

All of these settings are the recommended settings for Orabuntu-LXC.

Shutdown the VM and take a pre-install snapshot of the fully ready machine prior to Orabuntu-LXC v7 LXD install.  Suggested naming for the snapshot(s) of the cluster VMs are shown in the screenshot below.  After getting a snapshot of each VM in its "vanilla" state fully-configured and ready for the Orabuntu-LXC install, start the HUB HOST VM which in this guide, is named OLXD-1.

Once the HUB HOST is up, login from a terminal and verify the status of the ZFS storage pool as shown below.

These variables are set already and should not need to be changed.  Inspect the anylinux-services.HUB.HOST.sh file and "cat" or "more" the file to inspect any other variables that are of interest to you. Do not change any settings unless you are using the software in an "expert" mode.

Additional GRE HOSTS can be added to the LXD multi-host network by following the same steps for adding GRE hosts as shown above, but be sure to edit the SPOKE IP address for each new GRE HOST, while continuing to use the same HUB IP address in the "anylinux-services.GRE.HOST.sh" file for each new GRE host to be added to the LXD cluster.

See screenshots below of network and storage settings for the Orabuntu-LXC v7 GRE HOST

Figures 2.1 Details of LUN for /dev/sdb for ZFS mirrored storage pool olxc-002

Figure 2.2 Details of storage LUN for /dev/sdc for ZFS mirrored storage pool olxc-002

Figure 2.3 Details of networking for Orabuntu-LXC v7 GRE HOST

The steps to prepare an Orabuntu-LXC GRE HOST to join into a cluster with the Orabuntu-LXC HUB HOST are a repeat of the above.  Update, upgrade, install required packages, add ZFS storage pool LUNs, and create the ZFS 25Gb mirrored storage pool EXCEPT that you MUST name the storage pool on the GRE HOST as follows:

olxc-002

and if you add a second GRE HOST to create a cluster of threeLXD hosts then the second GRE HOST ZFS POOL will be named:

olxc-003

and so on.  Otherwise, the configuration is the same.