Expanding BTRFS 8tb & 1tb?

[DigitalLF]

Hi!

 

I got a array that now is 5x 8TB drives and i would like to add 2x 1TB drives just to use as mirrored backup drives.

 

Can i just add them to the array or should they be mounted with "Unassigned Devices"?

 

Or is this just my Hardware RAID mindset? How would you do it?

 

 

Also another question about expanding. what happens if lets say i would throw a bunch of more disks in there would i still just have 2 parity drives? seems a bit risky?

[tdallen]

I think it is your hardware array mindset.  There is one storage array in unRAID.  If you add two 1TB drives to the parity protected storage array you will increase its capacity by 2TB.  There is no way to specify an independent redundancy scheme for these two drives (unless you use them as cache disks or hide them behind a hardware RAID controller).  You can add them to the parity protected array or mount them independently via Unassigned Devices - up to you.  If you add a bunch of data disks you still have two parity disks - you might want to do some reading:

 

https://lime-technology.com/wiki/UnRAID_6/Overview#Parity-Protected_Array

 

Is dual parity risky?  Not really, though there are certainly more conservative schemes.  Dual parity protects you from two simultaneous disk failures.  If you experience a failure you need to act promptly to address it.  Dual parity isn’t very risky,  but running your array in a degraded state is.  Dual parity isn’t risky, but populating your entire array with the same model of the same disk all purchased at the same time and then trying to run them for 7 years is.  unRAID parity and dual parity protection is quite effective and a good cost/benefit compromise compared to more complex systems, but it does require some thought.  Oh, and running without notifications turned on is risky -  turn on notifications!