Which ZFS layout would you use for the following, and why?

[soulburn]

Hardware/environment
24 drive bay case
4TB drives, all same make/model/etc., purchased within last year so not all same manufacturing lot
64 GB RAM.
Home use
Mainly for personal data, home office backup, ESXi homelab datastore.
Max 2-3 machines will access data at once.

Possible ZFS configurations, arranged by number of disks
20 disks
raidz2 = 1 zpool, 2 vdevs of 10 disks, 2 can fail per vdev, 4 can fail in total
32TB per vdev, 64TB total usable, 20% of total drives can fail

22 disks
raidz3 = 1 zpool, 2 vdevs of 11 disks, 3 can fail per vdev, 6 can fail in total
32TB per vdev, 64TB total usable, 27.27% of the drives can fail

24 disks
raidz2 = 1 zpool, 3 vdevs of 8 disks, 2 can fail per vdev, 6 can fail in total
24TB per vdev, 72TB total usable, 25% of total drives can fail

Or should I go for something else?

 

[Ericloewe]

I'd do four 6-disk RAIDZ2 vdevs. I feel it would balance data safety with performance. If you're doing ESXi, you'll need the performance.

 

[soulburn]

I'd do four 6-disk RAIDZ2 vdevs. I feel it would balance data safety with performance. If you're doing ESXi, you'll need the performance.

Thanks for the reply, Ericloewe. The more I think about it and based on others feedback, I think it may be better if I go with 2 separate zpools as it will be easier to manage in the long run. With that said, I've narrowed it down to the following:

20 disks
raid z2 = 2 zpools, 2 vdevs of 10 disks, 2 can fail per vdev, 4 can fail in total
32TB per zpool, 64TB total usable, 20% of total drives can fail

22 disks
raid z3 = 2 zpools, 2 vdevs of 11 disks, 3 can fail per vdev, 6 can fail in total
32TB per zpool, 64TB total usable, 27.27% of total drives can fail

24 disks
raid z2 = 2 zpools, 4 vdevs of 6 disks, 2 can fail per vdev, 8 can fail in total
32TB per zpool, 64TB total usable, 33.33% of total drives can fail

Thoughts?

 

[anodos]

Go with more vdevs. With ESXI you'll want the IOPS. From what I've read, a RAIDZ2 vdev has the IOPS write performance of a single disk. See here: https://blogs.oracle.com/relling/entry/zfs_raid_recommendations_space_performance

 

[cyberjock]

If you plan to do VMs you should give up on everything except mirrors. Otherwise I'd do 8 disk RAIDZ2 vdevs and call it good. Yes, there's the whole "its not optimal" but the reality of it is that since 9.2.0 has made compression the default ZFS setting there is no longer such a thing as "optimal" as your block size will always vary thanks to compression.

 

[soulburn]

I think I'll settle on the following:

2x 10 disk z2 zpools
1x 4 disk zpool mirror dedicated for ESXi datastore

Thanks for the help everyone!