Adding a second drive to mirror the original

[Brewboy]

I'm running 11.3 U4.1. I have a single 8 TB drive and I want to add a second 6 TB drive to mirror it. I realize that my capacity will be reduced to 6TB, but I really don't need the full 8 anyway.

I mirrored my USB boot drive through the GUI and everythingwent well, but I don't see the options to attach another storage drive. My original drive is ADA0 and the new drive is ADA1.

 

[Patrick M. Hausen]

That is not possible. The vdev has got a size of 8T, so you can only attach a second drive of 8T or larger. Shrinking of vdevs is not possible.

You can, though

• create a second pool on your 6T drive
• copy the data over
• remove the first pool
• attach the 8T drive to the 6T vdev

I recommend reading the ZFS Primer, which is part of the FreeNAS documentation.

 

[Fredda]

Add a mirror drive to an existing single disk vdev:

Create zfs mirror by adding a drive?

Yes, and I also posted more than 2 years ago that these steps aren't correct for the latest version of FreeNAS, which is now an ancient 2014 version. The reality is that nobody should be using this guide anymore. :P

www.ixsystems.com

I'm not sure if it will work, as your added drive is smaller than you pool drive.
In that case you'll have to move your data over to the smaller drive first and and add the bigger drive back.

 

[Patrick M. Hausen]

I'm not sure if it will work, as your added drive is smaller than you pool drive.

It won't for precisely that reason.

 

[Brewboy]

I guess this would be much easier to do if my new drive matched the capacity of the initial one.

 

[Brewboy]

I've created a new pool. Copied everything from the large drive to the smaller drive. I disconnected the large drive and wiped it, but I do not see a way to attach it like I did with mirroring a boot USB drive. Can this de done in the GUI?