ZFS Pool Changes

Anyone have good metrics on ZFS performance?

This is probably the most know article I have seen on it, but Doesn’t really have the options I am looking at…

Currently Debating RZ2 6x8tb(4 usable) drives or going to RZ3 8x8tb(5 usable)
also debating RZ2x2 4x8tb++4x8tb (4 usable)

Another good write up

asked by AlanObject on 03:54PM - 12 Nov 17 UTC

Article Linked in the above topic says:
" For raidz2, do not use less than 6 disks, nor more than 10 disks in each vdev (8 is a typical average)."
(Article link: http://nex7.blogspot.com/2013/03/readme1st.html)

My current setup is RZ3 8x3tb, that I am at over 90% capacity on


WD White/Red mix of 8TB drives 6-8 Drives
Also I have 10gbe so I can use more performance
Home Environment

RZ3 8drives
RZ2 6 drives
RZ2+RZ2 4++4 Drives

Goals Performance/Reliability balance.

(Note: I appreciate all help, but would like your rationale on your decision)

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I’ve only tested my own setup of RZ2 8x4tb drives. I’m running FreeNAS as a VM with a Dell Perc H200 flashed to IT mode passed through to it. Below are the Crystal Discmark results:

CDM%20-%20FreeNAS%20CIFS%20initial%20test CDM%20-%20FreeNAS%20iSCSI%20Drive%20initial%20test


A bit better then my 8x3tb reds in rz3

Forgot to mention, pool block size is 128k, though unsure how much this impacts performance

Ordered 3 more 8tb so ill be at 6 total, gonna set up that in RZ2 and do some testing


All drives are shucked and in the server, sadly after a 1.5hrs of troubleshoorting 3/4 of my white lables (my new 3) need the 3v pin mod so just ordered some tape to do the mod. So should have some updates sunday.


After taping off the 3 pins, all drives showed up. Starting migration of data now.


Max write seems to be around 470MBps

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That’s 6 8TB RZ2 + incompressible data?

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Seems about right for that configuration

Yep from the other pool need to set up my 10gbe direct connect to test a bit more later

Just moved all my data onto the 8td pool
I decided on my old 3tb drives to make a pool of 3 vdevs of 2 drive mirrors with 2 spares (as they are older drives now and I dont car about storage efficiency as 8tb should be plenty)

have a lot of testing to do but pretty happy with my new set up

I have an old samsung 850 pro 256gb drive i can throw in somewhere.

I’d be interested in seeing what your performance is like with 3 vdevs of 2 drive mirrors can do performance wise in comparison. While I can’t really swap to it, eventually I’d love to be able to swap out my 8x4tb RaidZ2 array to something like 4 vdevs of 2 with 10tb drives once my media library hits that point.

Might be awhile for an in-depth look school just started back up so time is lacking

No worries. I’m gonna be in a similar boat somewhat soon (depending on how fast transcripts get transfered)