>> What's the current recommendations around raid capacity before you have to seriously start worrying about drive failure before it can be rebuilt?
That depends on the size of your drives and the number in the array. If you are running a small NAS with only one parity drive, you don't want drives that take more than a day to onboard. That limits you to 4/6TB per drive. If you have two parity drives in the array you can probably risk the 8/10/12 TB size. If you are running commercial-scale arrays of dozen of drives, arrays that can handle multiple failures at once, then the sky is probably the limit.
But the story gets more complicated. Are all of your drives the same age? Are all the drives of the same model/manufacturer? Such things increase the risk ofone failure evolving into a multi-drive failure during rebuild. If/when I build a new array I want drives of different ages. So If I had 10 drives, I would start the array on five or six, holding some for later so that the entire array isn't the same age.
That depends on the size of your drives and the number in the array. If you are running a small NAS with only one parity drive, you don't want drives that take more than a day to onboard. That limits you to 4/6TB per drive. If you have two parity drives in the array you can probably risk the 8/10/12 TB size. If you are running commercial-scale arrays of dozen of drives, arrays that can handle multiple failures at once, then the sky is probably the limit.
But the story gets more complicated. Are all of your drives the same age? Are all the drives of the same model/manufacturer? Such things increase the risk ofone failure evolving into a multi-drive failure during rebuild. If/when I build a new array I want drives of different ages. So If I had 10 drives, I would start the array on five or six, holding some for later so that the entire array isn't the same age.