Was just thinking about what I would do when a drive fails on me.  I have a 5TB parity and 3 data drives (5TB/2TB/2TB).  I do not have hot spares available.

 

If a drive failed, of course I'd want to replace ASAP, but does that mean I need to go to my local store and buy a replacement that day or can it hold out waiting 2 days for an Amazon Prime shipment? 

 

Is there any sort of time limit on how long parity keeps the ability to rebuild the drive or is it more along the lines of, as long as I don't write anything further to the remaining array, there is an indefinite time limit?

You can last as long as the other drives remain valid. If we know exactly how long that was, we'd buy lottery tickets and retire off the winnings. 

Your time limit is when another of your disks fails. Parity does not have the ability to rebuild any drive on its own. To do that you need parity and all the other disks to be perfectly readable. You can however continue to write to the array, including the missing disk as its contents are emulated. The safest thing to do in your position is to shut down your server until you have a spare disk available but you can continue to use it if you need to, as long as you understand and accept the risk.

Ah, got it.  Thank you both!

I think honestly I went 7 or so days. I shut down server for 3 of the first days out of nervousness and then decided to let it roll. 

Everything turned out in the end, but yeah it felt weird knowing that I had a drive that was literally down and everything was working just fine. 

 

I did however make sure that I didn't write any new content to that missing drive just as a precaution. I'm sure it would of been fine if I did, but I just didn't want to take any chances.