Question about parity, rebuilds, and larger hard drives

[keefd]

Here's my current array layout:

P - 12TB

1-4 - 12TB

5 - 5TB

6 - 2TB

 

What I'm wondering is - if either drive #5 or #6 dies and I got a 14TB drive or larger replacement, what's the best way to incorporate that new drive into the array?

 

I know that in my case for a healthy array I would just simply swap the parity drive for a 14+TB drive, but at the moment I can only think of replacing the data drive with the 14TB drive and losing the 2TB extra capacity if one data drive has already failed.

 

Is it possible to shut the array down and clone the parity drive to the 14TB drive so that I wouldn't have to do a full parity calculation, and put the old 12TB parity in place of drive #5 or #6? Or if I can't clone it, how can I put the new 14TB drive in as parity and put the 12TB parity as a data drive, assuming 1 data drive is dead?

 

Thank you.

[JonathanM]

https://wiki.unraid.net/The_parity_swap_procedure

[keefd]

53 minutes ago, jonathanm said:

https://wiki.unraid.net/The_parity_swap_procedure

Ah! I should have known that documentation like that would have been available.

Thank you for pointing that out.

 

edit - I was asking because 14TB drives are on crazy sale right now, but I have only 9TB out of 55TB currently used and I do not need more space. I'd prefer to upgrade later on, but if a drive failed that would of course mean I'd have to do that very soon.

Edited November 22, 2020 by keefd
Clarity.

[JonathanM]

1 hour ago, keefd said:

but I have only 9TB out of 55TB currently used

I don't recommend having that much unused space, as each spinning drive adds a failure point, more power consumption and heat, and wasted powered up hours. As a rule of thumb I only add drives when the unused space is smaller than my largest drive.

[keefd]

I originally bought them for a zfs build, hence the 5x12TB drives, the 5 and 2TB I just had spare. You do have a point, however, and I given that I'd probably build it differently if I did it again. I do set unRAID to power them down after 2 hours.