Utilising and Exploring ZFS to its Potential (A Quick Guide)

Have you seen the Drobo box? it’s a SAN that allows you to create giant volumes and hot swap out hard drives at will with failure tolerance… bad news, is that it costs close to £1000 even without the drives, i’ll explain how to make a better one… for free! =).

ZFS (Zettabyte Filing System) is Sun’s newest file-system offering, its supported on FreeBSD / Solaris natively and Mac OS X / Linux / Windows via third-party utilities. I’m gonna keep this guide, simple, short and sweet, so i’ll bullet list the main features that wow people about ZFS =)

  • It can store up to 340 quadrillion zettabytes of data (no other production filing system can do this)
  • It checksum’s your data on the fly so you can check for integrity by “scrubbing” it (identifying broken drives before they completely die)
  • It supports every raid configuration you can think of natively and doesn’t suffer from the raid5 data-hole.
  • You can create snapshots of your data that do not waste hdd capacity.
  • Volumes or “Pools” can be expanded at any time, so you can start with a 2tb raid, and increase it to a 10tb raid with no data loss.
  • You can mix/match capacities, brands, rpm’s of drives.
  • Its reliable* (on officially supported incarnations anyway)
  • Its a memory whore (don’t try it unless you have 2gb ram on your system)
  • Its supported in the latest version of FreeNAS (0.7)
  • Allows hotplugging of drives when one fails (so you don’t lose data/time)
  • Hotspares are supported
  • Can be easily transferred / transported to any other ZFS supported system without extensive configuration or any data loss.
  • Its free free free free (under CDDL).

Think of a hardware raid5 or a geom_concat/raid and then think about those again, but without any of the issues / flaws they have… thats what ZFS is! =)

So lets get started, I’ll run through creating and bringing a ZFS raid online first, and then some maintenance commands afterwards. I suggest trying this on a … 


Build a Free NAS using… FreeNAS with SMB/AFP/iTunes/iSCSI Targets

If you want all of your storage in one centralised place, that is accessible using just about any protocol out there, then you’ll need Network Accessible Storage (NAS), This can be often very expensive, upwards of £1,000, however you should firstly try FreeNAS, its a project based upon FreeBSD which provides a very comprehensive NAS environment supporting all common protocols including iSCSI, so you can even set Vmware to boot from hard disks stored on your FreeNAS! The whole thing is a bare-metal installer, and runs on any hardware manufactured within the past 10 years or so! Although for iSCSI you’ll need a minimum of 256mb Memory. So try it out, tell me what you think. Personally… I LOVE IT!, I’ll be posting a tutorial on getting VMware to use an iSCSI target defined with FreeNAS Later! Until then grab FreeNAS here P.S. it supports IPV6 =)

My FreeNAS Server

My FreeNAS Server