Warnings encountered when extending RAID0 pool

[be7taname]

My freenas has a pool which consists of two 5TB disks in RAID0 (no raid basically) shown below.

I am trying to extend this pool, so I added two 8TB disks into the machine.
First I extended the pool with one 8TB disk and I got the warning "You are trying to add a virtual device consisting of 1 device(s) in a pool that has a virtual device consisting of 2 device(s)" as shown below.

Therefore, I added the 2nd 8TB disk into the new vdev. However, I got one more warning "Adding data vdevs with different numbers of disks is not recommended. First vdev has 1 disks, new vdev has 2." on top of the previous warning as shown below.

I am totally confused by the 2nd warning since my current vdev, as shown in the 1st picture, consists of two disks.
Please advise how I could extend my pool safely. Thanks in advance!

 

[sretalla]

I don't doubt that the wording of the warnings wasn't considering the case of a striped pool when trying to help people to accidentally not add a VDEV of the wrong type into a pool with existing VDEVs.

You can log a ticket in jira if you think it's really impossible to understand.

A quick set of tests on my end show that the pool correctly becomes a stripe of 4 single-disk VDEVS when adding 2 to an existing 2 despite the strange warning.

 

[be7taname]

Thanks @sretalla ! If that's the case, I will just ignore the warning. Could you please help to do another test to see if it becomes a stripe of 3 disks VDEV when adding 1 to an existing 2 if not too troublesome for you? Many many thanks!

 

[sretalla]

It does.

 

[be7taname]

Thank you so much for the quick response and great help, @sretalla !
I tried to add 1 disk but the freenas simply wouldn't let me to go through.
So I added 2 disks and it worked. Again, I really appreciate your help!

 

[sretalla]

I tested on 12.0-U2. Maybe your different experience was from another version.

 

[be7taname]

Yes, I am using a different version FreeNAS-11.2-U7. It could be the reason. I was stuck in a infinity loop of "Confirm" and "Warning".