Advice for how to arrange my array?

[rmac35]

Hi Everyone, just looking for some pointers on best way to go forward in relation to arranging my disks as I don't think it is as simple as I thought.

 

I run unraid as a VM on esxi, for the past year or two I have been very happy running it with with 2x 8tb drives with one of them as parity drive.

 

I have recently started filling it up so decided to expand it and I got myself another 2x 8tb drives (I paid a bit more for nas ones this time) and my naïve intention was to expand by another 8tb and add a second parity drive.

 

But is having 2x parity drives in an array of only 4x disks a bit overkill?  I am trying to figure out if 2x parity is stupid in a 4 disk array?

 

The data on the array consists of backups of all our devices in the house + a media collection.    Loosing the backups would not be a real problem as long as one of my devices didn't have a failure at the same time, and the media collection would suck to loose but it is not absolutely irreplaceable/critical.

 

I am thinking maybe a better idea than 2x parity would be to keep the 4th disk separate from the array and do a cronjob copy type backup of my media collection to it?  But then I don't think its possible with unraid to present a disk on it's own?   Also baring in mind that I now have 2x older cheap 8tb drives and 2x new slightly more pricey 8tb nas drives.    Basically I don't know best way to set it up and am curious what any of you more experienced unraid guys would be thinking? 

 

Thanks in advance!