Migrate data in 1 x 12TB array to 4 x 3TB array

[McTaurus13]

Hi There,

   I started a journey of upgrading my server solution from an old Ubuntu NAS/Plex box to newer hardware on an Unraid trial. The Ubuntu server had a 4 x 3TB raid array setup and I copied everything over to a 12 TB (1 drive no parity) array on the new server. I ended up really liking Unraid and bought the full license and now I would like to move the old array into the current system, with the end goal of moving the 12TB drive out of the system. The problem is that there doesn't seem to be a strait forward path on how to do this. I'm looking for advice on how to move forward. 
My thoughts is that I could delete the current array, then create the new array with the 4 x 3TB drives (note I am also adding 1 x 4TB drive for parity. All drives except for the 12TB drive have been pre-cleared), and then copy the data over from the 12 TB drive to the array using the command line. 
What would you kind folks advise in this situation? Thanks in advance. 

[trurl]

7 minutes ago, McTaurus13 said:

copy the data over from the 12 TB drive to the array

Sounds like a plan, with the Unassigned Devices plugin. 

[McTaurus13]

22 hours ago, trurl said:

Sounds like a plan, with the Unassigned Devices plugin. 

Is there an easy way to export/ import my Docker and VM configurations? 

[trurl]

Do you have or plan to have cache?

[McTaurus13]

21 minutes ago, trurl said:

Do you have or plan to have cache?

Yes, I do have a 1 TB SSD cache enabled on the server. 

[McTaurus13]

What if, when I go to 'New Config' to reset the array, I preserve the "Data slots". Then after the new array is started I recreate the docker.img and libvirt.img similar to the procedure outline here?:

 

https://forums.unraid.net/topic/57181-docker-faq/?do=findComment&comment=564309

 

Edited August 12, 2020 by McTaurus13
correcting link