Raid 5 or 6 for NAS

[JJ2012]

Hi

I'm hoping to build a NAS from a computer I bought second hand. I know only what I have been reading and watching on YouTube so would like some advice please.

Should I set it up as a raid 5, 6 or not at all?

I'm hoping to use WD red drives - not sure what size yet.

Is it a bad idea to buy second hand hdds?

TIA

 

[USAFRet]

Which RAID type depends on your personal needs.

In my Qnap NAS I have RAID 5, 4 x 4TB drives.
Block level striping, with 1 drive worth of parity. It will survive the loss on 1 drive, with no data loss.

4 x 4TB drives in RAID 5 = ~10.5-11TB of actual drive space.

RAID 6 = block level striping, with 2 drives worth of parity. It will survive the simultaneous loss of 2 drives, but at the cost of less actual drive space for you to use.

Read more here:
https://en.wikipedia.org/wiki/Standard_RAID_levels#Comparison

 

[JJ2012]

So raid 5 is better in terms of space available and raid 6 is better I terms of risk. What about used he'd is this a bad idea?

 

[USAFRet]

So raid 5 is better in terms of space available and raid 6 is better I terms of risk. What about used he'd is this a bad idea?

Personally, I wouldn't get used hard drives.
Prices are just to cheap to go with used.

I just got 4 x 4TB Seagate IronWolf drives....$~125 each. 'Used' drives would have to be in the $25 range for me to consider. But then, if they are sold that cheap, how much have they been used and abused.


And also...RAID of any type is not a backup. I also have the entire NAS box contents backed up weekly to a whole other drive.

 

[JJ2012]

Ok great thanks very much. New hdds it is!