8 4TB disk, 1 * RAIDZ or 1 * RAIDZ2 or other recomendations

[bennyboy84]

I know this has been discussed to death but i could not find a thread on the Nas4free fourms.
Good one at https://forums.freenas.org/index.php?th ... onfig.158/ with many commnets from users now on/running nas4free.

But most post are from a number of years ago
Whats also throwing me is optimal number of devices because the ZFS best practices list this
http://www.solarisinternals.com/wiki/in ... mendations
Start a single-parity RAIDZ (raidz) configuration at 3 disks (2+1)
Start a double-parity RAIDZ (raidz2) configuration at 6 disks (4+2)
Start a triple-parity RAIDZ (raidz3) configuration at 9 disks (6+3)

But nas4free when creating a vdev list this
Note:
Make sure to select the optimal number of devices:
RAID-Z1 should have 3, 5, or 9 disks in each vdev.
RAID-Z2 should have 4, 6, or 10 disks in each vdev.
RAID-Z3 should have 5, 7, or 11 disks in each vdev.


Re building a new server
Old setup had 5 4TB disks in a RAIDZ2 setup
Have backed up all the data and have 3 more 4TB disk, making 8 in total

Should i create 1 * 8 disk RAIDZ2 setup
or
2 * 4 RAIDZ setup and add them to the one pool?
or 5 + 3 RAIDZ setup
or get another drive

My thinking + & -
1 x 8 disk RAIDZ2
+ 2 drives can fail
- longer rebuild time?
- Much longer scrub time

2 * 4 RAIDZ in one pool
+ quicker scrub time, can set up diffrent date per vdev
+ quicker rebuild time?
+ quicker upgrade path, as i can afford to replace 4 dirves over time instead of 8 to grow the vdev
- Only one drive can fail per vdev

Both would have the same available space
Both not listed as optimal number of devices


I have had 2 drives fail in the past, lucky it was a 5 disc RAIDZ2. Was using WD 2TB green drives at the time not designed for always one ect. So i do sway towards RAIDZ2

[raulfg3]

optimal number of drives is this only optimal, not optimal number of drives is not noticeable for a home NAS .

my sugest is 2x4 hd = 2 vdev of 4 disk, and a big pool of this 2 vdev.

big advantage of this config is that you can add other 4 disk (one new vdev) and grow your pool.
pd: if you choose 8xraidz2 you need 8 disk to grow your pool.

[bennyboy84]

optimal number of drives is this only optimal, not optimal number of drives is not noticeable for a home NAS .

my sugest is 2x4 hd = 2 vdev of 4 disk, and a big pool of this 2 vdev.

big advantage of this config is that you can add other 4 disk (one new vdev) and grow your pool.
pd: if you choose 8xraidz2 you need 8 disk to grow your pool.

Yep, i think in the long run its the best option.
Thank you

If only hdd had dropped in price like they use to. I went from 2tb drives, to 4tb drives for the same price over a few years. Few years later im still buying 4tb drives for the same price.

[apollo567]

If only hdd had dropped in price like they use to. I went from 2tb drives, to 4tb drives for the same price over a few years. Few years later im still buying 4tb drives for the same price.

Well an oligopole has only a limited need to lower prices.....