Transition from FreeNAS to UnRAID


Jan 16, 2014
Nashville, TN
I posted this question on the UnRAID forum, in the ZFS for UnRAID section and didn't get a ton of traction. I am looking for advice on how to move to UnRAID, and best practices for ZFS on UnRAID once moved. I am currently running FreeNAS 11.3 and am planning on moving to UnRAID for the better VM and docker support. Currently in FreeNAS I have three pools, the boot drive, a mirrored SSD set I used for a VM and my 8 x 4TB WD Red Z2 pool. Once on Unraid, I still want my main storage pool as ZFS Z2. However, I don't want to risk any Data loss during the transition. My loose plan is to sync all data to either a pair of mirrored Seagate Exos X16 16TB drives or copy the data to the two drives with them mounted as regular drives. Then once running Unraid, rebuild my big Z2 array, copy the data over without permissions and then rebuild two of the drives with the 16TB drives swapped for two of the 4TB drives. Is this a good plan, should I do something else?



Active Member
May 27, 2019
Austin, TX
So since you're in the US for the cost of two 16TB Exos you could have a 5x 8TB WD White Shuck array (which would yield 3x8TB data array with dual redundancy).
Those are the best cost per GB anywhere pretty much and equivalent to WD Red 5400 rpm drives you have (depending on your PSU you might have to deal with the 3.3v pin issue though), which you would just need some molex to sata connectors or to clip the 3.3v power line. I'm running a dozen of those in my unraid arrays after popping them out of the shells.

So if you have an older computer/hardware that you'd were planning on using to sync those 16TB that is the best route IMO, build your unaid to run along side the ZFS box while you migrate (minus the ssd for vms that you would move/rebuild later). Then once you're good to go migrate the OS flash drive and your 8TB drives to the original box. I recommend this guy for the unraid flash drive, its usb 2.0 so low heat generation, low profile, and plenty of space for any logs (mine is using <1gb currently in my unraid setup).

After thats all said and done, then you could add three of those 4TB drives to the unraid array for more space, or keep the zfs as a backup array even. I'm super paranoid about data loss so I'm running two unraid arrays with mirrored data each w/ dual disk redundancy. I've had good luck with those WD 8TB shucks none bad so far after several years of running 24/7 (most are at 20k+ hours now and still going strong, I keep a cold spare on hand).

PM me if you want and we can hit up a discord or something and chat directly about your specific setup and any configuration tips/tweaks ya might need.