Hello all,

 

New unRAID user here and let me say how happy I am that I found this tool and community!  I tried searching the forums and could not find this exact question so thought I'd has it.

 

I currently have 2 data drives and 1 parity drive in my system.  All drives are 2TB drives and 2 of them were clean when they went in.  I precleared and formatted the two clean drives and proceeded to copy all my media from my other 2TB drive via external enclosure to the new array.  I then put the old 2TB drive in (Still NTFS format with 1TB of data on it) and chose it as my parity drive.  I expected to see an unformatted drive like the others and then it would format but instead it started to parity sync.  My question is, did it need to be formatted or is the parity sync literally overwriting every bit with a 0/1 therefore overwriting everything on the disk?  I just want to be sure my parity drive will be ready to go in the event of a drive failure.

...  I expected to see an unformatted drive like the others and then it would format but instead it started to parity sync.  My question is, did it need to be formatted or is the parity sync literally overwriting every bit with a 0/1 therefore overwriting everything on the disk?...

The parity drive does not have a File System so no format.

 

While it is not necessary you can also preclear a drive before assigning it as parity just to give it a good testing.

 

The parity drive does not have a File System so no format.

 

While it is not necessary you can also preclear a drive before assigning it as parity just to give it a good testing.

 

Since you're using this drive as your parity drive, you should really preclear it (on drives that have been used in other systems I  preclear 5 times, which may be overkill, but makes me feel a little bit better about putting the drive in my array).  For my parity drive I also did a preclear x5.

 

For what it's worth I took a drive from a small NAS device (DNS-323), and it failed on the 3rd preclear cycle (clicking).

The parity drive is partitioned (which happens when it's assigned) and then raw data is written to the partition. So, no filesystem and no formatting.