Hi, this is my first time building a NAS. First I was going to use FreeNAS, but the virtualization capabilities of UnRAID are very nice, I want to try it out.

 

For a little introduction, I bought this server for my NAS:

• Dell Poweredge R410
  
• 2 x Quad Core 2.40GHz E5620 Processors
  
• 24Gb Memory Installed ( 6 x 4GB )
  
• 1 X 146GB 15K 3.5IN SAS Hard Drive Installed (will use this as a cache disk)
  
• ONBOARD SAS 6/IR Raid Controller ( dell part# HM030)
  
• Dell iDRAC6 DRAC 6i Remote Access Board K869T Installed
  
• 480w Power Suppy
  

 

I will be using it to make a NAS for my home office, so me and my roommates can share entertainment files, as well as work-related files (we're freelancers). I also want to run a Windows 2012 VM to virtualize some Windows-only business software we need to use on our Macs, and a Linux VM to use as our sandbox for software development.

 

It seems that UnRAID can handle this easily.

 

Now I need to buy the hard drives. I found these Certified Refurbished HGST Enterprise Ultrastar 3TB drives on Amazon: https://www.amazon.com/HGST-Ultrastar-HUS724030ALE641-Enterprise-Refurbished/dp/B01LYVD7ME/ref=sr_1_1?ie=UTF8&qid=1483068884&sr=8-1&keywords=refurbished+3tb

 

Judging by the reviews, they seem solid, and the price is great for 7.2k RPM drives. I plan on testing the disks thoroughly before putting them in production. Has anyone used refurbished drives on their NAS? Is this a dumb idea?

 

Also, another question.

 

Let's say I get 2x3TB drives, and assign 1 for data and another for parity. What happens when I buy a third disk? Could it work like a RAID5 setup?

 

I don't quite understand how parity works in UnRAID. I see people using 6 data disks, with only 1 parity disk. How can data be safe when you only have 1 parity disk for that many drives?

 

How can I protect my data the most when having 3x3TB drives?

 

Sorry for asking so many questions.

 

Thanks for the help,

 

Vini

 

...  <SNIP>  ...

 

Let's say I get 2x3TB drives, and assign 1 for data and another for parity. What happens when I buy a third disk? Could it work like a RAID5 setup?

 

I don't quite understand how parity works in UnRAID. I see people using 6 data disks, with only 1 parity disk. How can data be safe when you only have 1 parity disk for that many drives?

 

How can I protect my data the most when having 3x3TB drives?

...  <SNIP>  ...

 

Vini

 

Rather than my trying to write out an explanation, read  LimeTech's explanation  on how the unRAID parity system works:

 

    http://lime-technology.com/wiki/index.php/UnRAID_Manual_6#Parity-Protected_Array

 

I have not heard personally of anyone using 'refurbished' drives.  The quotes are because there is no way that one can 'refurbish' a hard drive.  You can test it to see that it works and at least two folks even then got DOA drives.  If the quotes power-on times of 10,000 to 15,000 hours are accurate then they probably have a couple to (perhaps) four more years of life left.  But remember  that these drives were probably spun-up 100% of the time whereas most unRAID drives are probably spun-down 90% of the time. 

 

By the way, that ONBOARD SAS 6/IR may be an issue.  unRAID does not use a RAID controller.  Perhaps, it could be flashed to IT mode...