I began with a new 4tb parity drive as my original intent was just to use existing drives for the array, which are all 3+ years old but had not caused any issues I was aware of.  Before I began to permanently move all the media to its new home, I decided to go out and swap out the 4tb for a new 8tb as parity, as that is likely the size i will pick up when a data drive dies (plus best buy was selling them cheap).   I followed bjp's process of replacing a parity drive to swap the two, and went ahead and added an old WD Green 1.5tb drive that to my knowledge was healthy. Started the array, and parity is being rebuilt.  

 

The WD drive is showing SMART errors: 200 worst for both Current Pending sectors and Offline Uncorrectable, and is approaching 4 years of power on hours. 

 

• Do I junk it now or squeeze some more life out of it knowing I will have parity and multiple other drives?
  • If now, can I just cancel the rebuild so I can stop the array?
• Can I safely begin to move media onto the array during all of this?

 

 

Post diagnostics zip file if you want a more educated read on things.

 

Don't use any drives that you don't fully trust in the array. Keep in mind ALL drives must be read completely and flawlessly to recreate a missing drive, so if you leave a questionable drive in place, and one of your "known good / new" drives decides to fail without warning, you will likely lose data on both drives.

 

This is the reason many people won't add a drive to the array without it passing at least one preclear cycle.

Thanks for the response. The failing drive was in there since the start, when I precleared all of them 3 times with no issues. SMART errors did not start (or i didnt catch them) until this latest array change.  Diag also probably shows that I have an old UPS shutting things down occasionally, that will be remedied tonight.

tower-diagnostics-20170824-0845.zip

Re-read my question, and it is misleading.  When I "added" the WD drive as referenced above, I meant I had taken down the whole array and built from scratch with a new config, which is probably my third as I am learning on the fly.  However, before any configs, I had pre-cleared every drive involved 3x with no issues. Sorry for any confusion.

 

Don't spend too much time on this, as your above response has me thinking I should just get rid of it, and green drives don't last long anyway so I cant complain. I am curious if there is anything in the diag files that would indicate I should have done something differently though.

Run an extended SMART test on that disk, it's somewhat normal for WD disks to show false positives, SMART test result will confirm one way or the other.