Adding vdev's to an existing pool


Sep 7, 2021
I can't find the answer, and maybe that's down to my poor google skills, but in regards to adding vdevs:

I have RAIDZ2 6x4TB created in the GUI. If I want to add more drives, would it be correct to use use "zpool add -f -o ashift=12 <pool> raidz2 /dev/sd* and then list 6x4TB drives? This would give me RAID2-0 6x4TB and RAID2-1 6x4TB. Is this best practice, or should I create the whole thing at once?

Can I create a RAIDZ2 6x4TBx2 in one step in the GUI, or do I have to use the CLI?

And secondly, if I wanted to create a 3rd vdev, could I use the CLI to create a RAIDZ2 6x2TB?

I currently have no data on the pool, so I can destroy it and recreate it, but I don't have all 24x4TB drives at the moment, but if I can make the server utilising the full RAIDZ2 x4 vdevs, I will replace the drives over time. OR do I just make do with RAIDZ2 x2 vdevs, and add 2 more later, and do nothing to fix the data balancing later because it doesn't matter anyway?
You need to find the real disk id to add a vdev to the zfs pool. This is a little cumbersome. Its important not to use the "/dev/sda" disk format as this may change during boot or reboot as its dynamical and may make your pool degraded. To find the real disk id you need to ls the disk by-id folder.

ls /dev/disk/by-id -lha

You will get a output resembling something like this
/dev/disk/by-id/scsi-35000c500d9f56e0f -> ../../sdi /dev/disk/by-id/scsi-35000c500d9f4d797 -> ../../sdj /dev/disk/by-id/scsi-35000c500da3bdeeb -> ../../sdk /dev/disk/by-id/scsi-35000c500da3bad7b -> ../../sdl /dev/disk/by-id/scsi-35000c500da01388b -> ../../sdm /dev/disk/by-id/scsi-35000c500da3bd143 -> ../../sdn /dev/disk/by-id/scsi-35000c500d9e8843f -> ../../sdo /dev/disk/by-id/scsi-35000c500da3bd08f -> ../../sdp

When you have found the right disks to add you need to add them as a vdev to the pool like this

zpool add -f -o ashift=12 vmpool raidz2 /dev/disk/by-id/scsi-35000c500d9f56e0f /dev/disk/by-id/scsi-35000c500d9f4d797 /dev/disk/by-id/scsi-35000c500da3bdeeb /dev/disk/by-id/scsi-35000c500da3bad7b /dev/disk/by-id/scsi-35000c500da01388b /dev/disk/by-id/scsi-35000c500da3bd143 /dev/disk/by-id/scsi-35000c500d9e8843f /dev/disk/by-id/scsi-35000c500da3bd08f

Before adding vdev
Screenshot 2023-03-10 at 11.29.36.png
After adding vdev

Screenshot 2023-03-10 at 11.44.09.png
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