My current ZFS Pool setup is comprised of 3x 4tb hard drives. These are put into a Raid Z1. I would like to extend this pool now.
My plan is to add another Raid Z1 vdev with 3x 8tb drives to the pool.
I also though about buying an additional 4tb drive and rebuilding the pool as a set of striped mirrors (2x 4tb, 2x 4b, 2x 8tb) but I think that I don’t need that level of parity. Loosing half of your space seems a bit non economic for my use-case.
I read online about issues with Raid Z1 especially on larger drives but the definition of “larger drive” isn’t really constant. Striped mirrors are defiantly better for performance (read/write and resilvering), I don’t think that’s necessary for me though.
So my question is if my planned layout is a good idea especially in the future when I want to put an additional 3x 22tb vdev into the pool.
Personally, I wouldn’t go with RAIDZ1 for HDDs larger than 8 TB, that seems to be the general recommendation these days.
Setting up three VDEVs with such a wide capacity spread is unusual but possible.
As far as I know, ZFS will tend to fill the newer (larger) VDEVs first until the utilization percentages are balanced.
In the end, it really comes down to your personal risk tolerance, your use case, and whether you have reliable, consistent backups.
I tend to belong more to the RAIDZ camp rather than mirror setups…
Mainly because of the more efficient use of storage capacity.
Mirrors are more flexible, though, and they resilver faster.
From my perspective, a RAIDZ2 only really makes sense starting at five-wide (four-wide is the absolute lower limit).
So the choice between Z1 / Z2 / mirror is often also a matter of cost…
