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Creating SmartOS zones using UCARP

In the Zone

Article from ADMIN 24/2014

By Alessio Ciregia

We show how to create highly available SmartOS zones using UCARP.

SmartOS [1] is an open source and free Unix-like operating system based on the Illumos kernel, a fork of the discontinued OpenSolaris kernel. The main purpose of SmartOS is to run virtual machines, so it offers KVM or zones (also known as Solaris containers) as virtualization technologies.

In the philosophy of SmartOS, which is defined as a cloud platform or a virtualization platform, concepts like high availability (HA), data distribution, filesystem replication, high reliability, and so on, should all be delegated to the application layer.

This approach means that, except through laborious tricks, objects like shared storage for virtual machines (VMs) are not supported – the VMs' disk images cannot reside on iSCSI or NFS disks. Additionally, there are no distributed filesystems (e.g., GlusterFS or OCFS) or distributed block devices (e.g., DRBD), and you can forget about VMs' virtual IP addresses or load balancers (e.g., Keepalived or Linux IPVS) managed by the hypervisor.

Thus, every physical server does not share anything with other physical servers. In other words, there is no mechanism to achieve high availability from the hypervisors (e.g., using Heartbeat or Pacemaker) to start a VM on another hypervisor in case of failure of the server hosting it.

If you want high availability or high reliability, you have to be modern. You should learn concepts and technologies like Node.js, cloud storage (DS3), Lucene, MongoDB, Riak, REST, SaaS, and so on. Additionally, you have to forget the old-fashioned IP address bound to a specific service or welded to a specific machine providing a particular service. You probably have to rethink your applications.

I don't want to say that if you need a virtual machine running an HTTP server or you need a MySQL database or any other service, you cannot use SmartOS – go ahead! SmartOS is great. I just want to say that SmartOS was born as a

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