Best RAID config for 4 disk NAS home use

[Johno]

My QNAP 4 drive NAS currently has 2 3TB WD Red drives as RAID 1 which gives me around 2.7TB of storage, which is running low so I guess I need to fill those two empty drive bays.
One option to add two more of the same disks as a new volume configured as RAID 1, thus doubling my space but I'd wondering if there's a better approach using a different RAID config that's as fault tolerant? I have back ups of all my files so tearing down the existing two-drive volume to make a four-drive volume isn't an issue, if that's the best way forward?

What should I do?

 

[Internet Man]

Excellent discussion here: https://www.snbforums.com/threads/qnap-ts-451-raid-10.26249/

I would go with RAID 10 (1+0). I have not had good experiences with RAID 5, although I was using software RAID from Intel.

With RAID 10, two pairs of drives are configured as mirrors (RAID 1) giving you some redundancy for fault tolerance. Data is then striped across these two mirrored pairs using RAID 0 which gives you a performance benefit. You can lose one drive in each pair and still maintain your data. The downside is that you only get 50% of the capacity of all drives.

It's great that you have separate backups of important data too!

 

[coxhaus]

RAID 5 only gets good with more drives. I would span 2 drives and mirror the spanned drives, RAID10.
You get the speed increase of the striped drive and the read speed increase of the mirror.