Looking raidz1 various sized drives

[Dice]

Hello fellas :)

I've the intention to setup a scrap SSD pool to mitigate the 'smallest drive per vdev determining size' consequence. The drives are:
Raidz1: 500+500+(250+250)GB

Im aware this is outside the normal recommendations and ..the following implications.
Nevertheless, I'm looking for links, pointers, key-words for searching, overall work-flow descriptions ..or whatever else you can come up with for how to make this happen.

Cheers

 

[sretalla]

Raidz1: 500+500+(250+250)GB

What you're proposing actually means 4 x 250 in RAIDZ1 (=750 - the usual padding and reserved space)

You could probably get a better result by using a mirror of the 500s and a second mirror of the 250s (still gives you 750 usable, but would theoretically perform faster... also allows you to lose 1 of the 500 and 1 of the 250 without losing the pool... in the proposed case, 2 lost disks = total loss.

 

[Ericloewe]

If you really want to do that you'll have to GEOM RAID1 RAID0 them together before getting to ZFS.

 

[HoneyBadger]

If you really want to do that you'll have to GEOM RAID1 them together before getting to ZFS.

I think @Dice intends to GEOM RAID0 the two 250's together, and then add the "three 500GB" drives into a RAIDZ1 and get ~1TB usable.

I believe this is commonly referred to as "Tempting Fate" or "Inviting Murphy for a Visit"

 

[Dice]

GEOM RAID

Thanks for keyword! :)

I believe this is commonly referred to as "Tempting Fate" or "Inviting Murphy for a Visit"

hahah
yeah, that seems about right :P

I got the typo of Raid0 vs Raid1.
Looking through the docs right now: https://www.freebsd.org/doc/handbook/geom-striping.html
Once the stripe is created and mounted somewhere, and the geome_stripe.ko module loaded, it would be time to start looking into setting up the pool.
I wonder if the stripe would be identified by freeNAS GUI or if setting up the pool would require setup via CLI, followed by an 'import volume' to the GUI-side?

 

[Ericloewe]

I think @Dice intends to GEOM RAID0 the two 250's together, and then add the "three 500GB" drives into a RAIDZ1 and get ~1TB usable.

I believe this is commonly referred to as "Tempting Fate" or "Inviting Murphy for a Visit"

Bleh, RAID0 of course.