Transfer data from existing Raid 1 drives

[Brian Milner]

Searched for this so forgive me if this has already been covered. I have two small NAS units now that both have 2 2TB drives in them (4 2TB drives). Both units are operating on Raid 1 so that there is 4 TB of total storage across the devices. I am looking to roll my own FreeNAS server instead and would like to make use of these 4 2TB drives in a new FreeNAS system. Question is what is the best way to do this in FreeNAS? Should I change my drives to linear mode so that they aren't mirrored first and then wipe two of them to start setting up FreeNAS? Do I need to purchase additional hard drives? I'd like the 4 drives to ultimately be a part of a single share on the new FreeNAS machine and contain all the data that is currently on those two systems. Obviously, FreeNAS would make better use of the 8 total TB of those discs. I want to do this the cleanest way possible with a reasonably high level percentage chance of not losing any data in the transfer.

 

[ian351c]

You mention already having 4x 2TB drives and also mention using 8 total drives with FreeNAS. Where are these four other drives coming from?

To answer your question: it depends. What is your use case (what type of data are you storing)? That will drive how much performance you require, which will pretty much tell you how you will do this. For regular home use (i.e. movies, pics, no big performance requirements), I'd recommend a RAID Z2 configuration for 6 drives. Buy the 4 other drives you were talking about, put your existing NASes into "linear" mode, build the RAID Z2 volume with the 4 new drives and 2 "old" drives. Transfer your data over. Then put your "linear" drives into one of your old NAS units, create a 4 GB striped volume and use it as a backup device.

The big risk here is the fact that you could lose all your data with the whole "linear mode" thing if you do it wrong. So be careful...

 

[Brian Milner]

Sorry if that was confusing. I want to at least make use of the 4 drives I have which are each 2TB. I'm open to buying more if needed but at the minimum I'm talking about using the 4 drives. The total storage size then for those 4 2TB drives is 8TB. That's where the 8 number came from. And, yes, I'm talking about storage for home use such as pictures, music, videos, etc.

 

[ian351c]

Cool. I'd do what I wrote then. :D