Zfs layout help

Level1Techs
1

I will admit when it comes to zfs vdev’s I thought it was pretty much set it and forget it. I always used the default settings with at least a raidz2 setup. I just upgraded my main server and got a good deal on 8TB drives.

My use case for this pool is mostly large media files. I have 15x8TB drives, my confusion is with vdevs. Should I have one 15-wide raidz3 or multiple smaller ones like 3x5-wide raidz2? My old setup was 8x4TB raidz2 but I’m not what the best practices are for going beyond 10 drives in a single vdev.

2

sweet baby hay suse

we like 6x drives in RAIDZ2 for ease of recovery
If you are not replacing your NAS every 3 years, account for a recovery and ask yourself,
“how many of my machines have 6+n SATA ports?”
N being host OS and recovery media, and or at least recovery media +1

I can make a decent living doing RAID recoveries, don’t be another client…

3

would a 5x3-wide raidz1 make sense?

1 Like
4

Not typically, but depends on your HBA, connections, and drives.

15 drives for us would be 5 drives of redundancy
10 drives usable
assuming you need the ENTIRE storage capacity in a single pool

5

These guys literally wrote the book on ZFS.

When I set up my workstation I had 16 drives to work with and I went with a single pool using four raidz1 vdevs each with four drives. 5x3 isn’t a bad idea either. I might decide to go with that plus a hot spare in the future. It’s about the same amount of usable space, but more IOPS, and the hot spare means I’d have to lose the wrong three drives all at once before Something Very Bad happened.

For a general purpose machine I probably wouldn’t use more than 8 drives in a single vdev. I’ve always found it difficult to find a legit use case for raidz3, but maybe that’s just me.

1 Like