[NV+ v2] 4 disks, 2 separate RAID-1 volumes?

StephenB wrote:
sticking with RAID-1 pairs is a good approach. It gives you more options if things go wrong.

Thanks StephenB.

Guys, didn't realize we were still dicsussing this. Yes, backups are still mandatory! I didn't mention my backup strategy in my original question because it wasn't relevant, but I see there has been speculation on my setup. I have a second NAS, I have USB drives, I have Dropbox. Despite this, I would prefer not to have to rely on my backups. Backups are more likely to get messed up than the original drives failing... I saw a scheduled backup system not execute for 3 months because something like an IP address got changed and nobody noticed. If one of my ReadyNAS drive fails, I still have all the data replicated on a 2nd drive, even stuff I changed 5 minutes earlier. It may not be quick or easy but I'm reasonably confident I can save all of that data. I will be honest -- I don't know how RAID-5 works, how 1 drive is sufficient to cover potential failure on 3 other drives. And when I have suffered one of those failures, and I am freaking out, is *not* when I want to have to learn.

PapaBear, I disagree with you on the idea of "wasted" space. All of us are dedicating a significant amount of our total storage capacity to replication/duplication/backup, it's just a matter of degree. In your setup, you have 8 disks (4 on the main NAS, 4 on the secondary) to hold 3 disks worth of data (37.5% capacity). You stated that if a drive fails in RAID-5, you need to go to your backup. So that implies that you can recover from only 1 failed drive. I have 6 disks (4 on the main NAS, 2 on the secondary) holding 2 disks worth of data (33.3% capacity). I'm OK trading that capacity loss for the benefit of being able to recover from 2 drive failures, even 3 or 4 as long as I don't get 3 fails on the same volume.

To go a little further, when I bought my first NAS around 2009, I paid $150 each for two 1.5TB drives, which was plenty of space for me at the time. Last month I decided to expand, so I bought two 3TB drives for $150 each. Thus my current primary NAS has 4.5TB of usable disk space in RAID-1, for which I paid $600. Had I gone with RAID-5, I would have had to buy 4 drives back in 2009. I would have paid $600, and had -- you guessed it -- 3x 1.5TB = 4.5TB of disk space. So it doesn't feel "wasted" to me.

I appreciate your comments and advice but wanted to eliminate the speculation over my reasoning for using RAID-1.