If you want the added space to have the same capabilities, yes. If you have a three drive raid-z1 vdev and you add one disk, the new disk will just be basic. You need to add another three drive raid-z1 vdev to truly expand the pool the right way. If you want to learn more about zfs, read this - https://pthree.org/2012/04/17/…l-zfs-on-debian-gnulinux/
Thank you for the link, I have checked it out, however do to some disabilities I usually cannot learn from reading documentation. I have scanned it over, and that appears to once again be the case here.
Moving on from that, yes, that is how I understood it, kind of.. But I thought you could add bigger vdevs, so long as they were (if you wanted the same fault tolerance) the same type of zraid.
So just top make sure I totally understand I would like to purpose a scenario to be sure I understand everything correctly.
I start off with a pool, like mentioned, with 3 50 GB drives in a vdev, raidz1, this gives me ~150 GB of space.
I create a second vdev, this time consisting of 4 drives of 75 GB each, in zraid1, and add it to the pool
Total space is ~150 + ~225 GB of space, total ~325.
This system would be considered "acceptable" by traditional standards.
It would have a fault tolerance of one drive. Or TWO drives (so long as the 2 drives were in different pools), but would fail is 2 drives failed in the same pool.
Please let me know if I got anything wrong, or if that basically sums it up. Or again, if I am totally way off..
Thanks again.