How should I use my disks?

[BobbyD1891]

Over the past few months I have been buying up Red drives in anticipation for my first freenas build. I am up to 10x3TB drives now so I was wondering how everyone thought I should set them up. I am trying to decide between a RaidZ2 using all 10 drives or a zpool with 2 vdevs, one using 6 disks in raidz2 and the remaining 4 in a raid z1. Other thoughts? I am not doing anything super performance oriented so more space would be a priority for me. Thanks

 

[Apollo]

Just a thought, but if you are going with 10 drives, why not doing RAIDZ3? This will be more secure than RAIDZ2.
On a day to day basis, you may not be after performance, but when it comes to doing scrubs, you may suffer from it.

 

[HoneyBadger]

Over the past few months I have been buying up Red drives in anticipation for my first freenas build. I am up to 10x3TB drives now so I was wondering how everyone thought I should set them up. I am trying to decide between a RaidZ2 using all 10 drives or a zpool with 2 vdevs, one using 6 disks in raidz2 and the remaining 4 in a raid z1. Other thoughts? I am not doing anything super performance oriented so more space would be a priority for me. Thanks

Don't mix different redundancy levels within a pool.

RAIDZ2 with 10 drives is an "optimal configuration" since you'll get 8 drives for data and 2 for parity. If you're going to go RAIDZ3 get an 11th drive.

 

[danb35]

RAIDZ2 with 10 drives is an "optimal configuration" since you'll get 8 drives for data and 2 for parity.

I thought we weren't doing the "optimal configuration" any more, what with compression and all? I'd still agree, though, that a single vdev of 10 x 3 TB in RAIDZ2 is probably the best configuration here.

 

[DrKK]

I thought we weren't doing the "optimal configuration" any more

I'm glad someone finally said this. The optimal configuration is more or less irrelevant in the grand scheme, now especially, but even before it didn't make a hell of a lot of difference to Joe Blow home user.

10x3TB in a RAID-Z2 is right at the edge of what I'd recommend, and I'm usually considered one of the most forgiving guys. I would say you're OK with that, but only barely.

 

[HoneyBadger]

Actually, there was quite a spirited discussion in another thread with regards to lost space, not performance, due to the alignment padding used with ashift=12. Despite being a power-of-two for data disk count, there's still a fair bit of space lost with 10 disks vs 6 or 18 (4 data/16 data). Original source which is also using 3TB drives as an example.

It looks like compression will help mitigate this significantly, but most home users are storing media data like JPG/MP3/MP4 which are generally incompressible enough to trigger the <12.5% early-abort in LZ4 and as such gets stored uncompressed.