SmartOS - a different kind of containers

This write-up aims to show you how to set up SmartOS with a mirrored disk pool and your first virtualised application in Node.js.

SmartOS has an impressive UNIX heritage going as far back as 1982 where its forefather SunOS was developed by Sun Microsystems. Since then some game-changer like Zones, DTrace, built-in KVM virtualization and ZFS have been added.

All of the above were combined by Joyent's Illumnos project to create a first-class, open-source hypervisor. Joyent deploy their operating system in the Triton which is similar to the Amazon's EC2 cloud.

Installation

SmartOS is designed to boot from a USB pen-drive so that all the disks in your machine are available for zones and VMs. You can also install SmartOS into a VM with Virtualbox but you may only be able to use Zones rather than all the KVM features due to nested virtualisation.

Booting from a USB pen-drive means you can easily upgrade the entire operating system.

On first boot you will need to provide:

  • an IP address or select by DHCP
  • a nameserver such as 8.8.8.8
  • the search domain
  • how to partition your disks
  • such as stripped, mirrored or RAID-Z
  • a root password

The machine will then reboot and you will see the login prompt. I don't think I've ever seen a server OS install so quickly, it's probably a tie for bringing up a new cloud image.

Checking everything

The first thing to do after logging in is to check out the ZFS pools created at install time. You should have a pool named zones.

By default there is no sudo command installed, but this is available from pkgin SmartOS's package manager.

# zpool list
NAME    SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
zones   148G  4.04G   144G         -     0%     2%  1.00x  ONLINE  -

Here's how you check the status of the pool:

zpool status
  pool: zones
 state: ONLINE
  scan: resilvered 4.04G in 0h1m with 0 errors on Wed Dec 14 23:10:56 2016
config:

	NAME        STATE     READ WRITE CKSUM
	zones       ONLINE       0     0     0
	  c2d0      ONLINE       0     0     0

errors: No known data errors

You can list your volumes with zfs list - this will include an area for the USB pen-drive's persistent configuration and any zones you set up will appear here too.

The zpool iostat command will show you what kind of bandwidth your drives are capable of.

# zpool iostat
               capacity     operations    bandwidth
pool        alloc   free   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
zones       4.04G   144G      0     30    236  2.04M

For more information on ZFS commands you can check out the Oracle Solaris ZFS Administration Guide or SmartOS ZFS technology page.

Wrapping up

That's as far as I got

Unfortunately I never had the time to fully write-up the rest of this tutorial, but I would think it may be a useful starting point for someone else. I wanted to release this for the community and I hope to see some of the usual spin-off blog posts.

If you'd like to see more, please reach out to me on Twitter @alexellisuk.

Alex Ellis

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