HDD Pools Question

[nov845]

Is it possible to three different pools of 4x16tb, 8x6tb, and 5x4tb with striping and parity as well as have the three pools show up as one drive?

 

[sretalla]

Is it possible to three different pools of 4x16tb, 8x6tb, and 5x4tb with striping and parity as well as have the three pools show up as one drive?

You're very mixed up on terminology, but mostly yes.

A pool can contain many VDEVs (but obviously, at least one).

A VDEV is made up of one or more drives with a toplogy of either stripe (no parity), Mirror (2 or more disks), or RAIDZ (either 1, 2, or 3 disks of parity in a sort of stripe with parity).

When there is more than one VDEV in a pool, the VDEVs are always striped together, meaning that each individual VDEV is crucial to the health of the pool (so the amount of redundancy/parity is important for each VDEV).

If one VDEV in the pool is lost due to sufficient failed members, the entire pool is lost.

What you seem to be proposing is 3 VDEVs (RAIDZ? 1 or 2) in a pool (certainly OK, but should be the same topology in all VDEVs, not one of RAIDZ1 and another 2 of RAIDZ2, for example) of different sizes (not best, but certainly OK) and different widths (number of drives in the VDEV, really not great to be different, but will "work"... performance will be unpredictable based on where data is going/coming from on the VDEVs).

For drives of the sizes you're mentioning, the forum recommends RAIDZ2 be used in all cases.