4 disk setup: VDevs, zpools and the likes

[heis2201]

Dear Community,
I have a question regarding the upcoming setup of my storage pool that so far I wasn't able to answer despite having read a bunch of threads, blogs and the famous slideshow. (Yes, I learned drives make up VDevs, Vdevs, make up pools, and that where you save your stuff...

I have 4x4TB drives that I would like to arrange in a RAID1 type setup. The idea: 8 TB net storage space, 8TB as mirror of that, one drive can fail. If it does fail, I simply want to replace it and the show goes on.

How Do I Do That? Is it

1.) two drives mirrored in a Vdev, and the other two drives in a second Vdev and together those 2 Vdevs form the storage pool? or
2.) two drives striped together in a Vdev, and the other two drives striped together in a second Vdevs, and together those 2 Vdevs form the storage pool?

(I know there is stuff like RAID1z and RAID2z but I don't see any real advantage of that - I must have an offline, off-site backup anyways.)

Thanks for your help!

 

[garm]

Ya, two mirror vdevs of two drives each is what you are looking for

 

[heis2201]

Just to be sure, I create a VDev in which I mirror the disks, I create a second Vdev in which I mirror two other drives, then I create a zpool of two VDevs.

Do I understand correctly: If any one drive fails, the Vdev will continue to function because it has a mirror within the same Vdev?

 

[garm]

It’s done in one command, https://www.ixsystems.com/documentation/freenas/11.3-U4/storage.html#creating-pools