Replace Drive without Taking Array Offline?

[halexh]

I have two drives in my array. One is a parity drive, and the other drive is going bad, but still very much usable and technically healthy according to unraid. Is it possible to replace the bad drive with a third, brand new drive without taking the array offline while I essentially clone (somehow) the bad drive's contents onto the new drive? All drives are the exact same size / model.

 

While the array is still online, I imagine new things will be written to the bad drive, which would require potentially running this cloning process (whatever that may be), multiple times, in order to get all of the data to the brand new drive.

 

Thanks

[Malakai]

You just shut down the server completely, remove the drive that is reported as going bad and replace it with the new drive. Turn the server back on and it will start up with the array not started and you can select the new drive in the spot that the failing drive was before and then start the array and it will rebuild the contents of the removed drive from the parity drive.

[Kilrah]

To expand, when you replace a drive it stays available during the rebuild process, albeit at reduced performance of course.

[halexh]

38 minutes ago, Kilrah said:

To expand, when you replace a drive it stays available during the rebuild process, albeit at reduced performance of course.

Thank you for that. I was about to ask, well isn't it going to spend the next 12+ hours rebuilding the new drive without the ability to read from it? Reduced performance is fine with me.

I'm assuming I will also be able to write to the array while this new drive is being rebuilt?

[itimpi]

3 minutes ago, halexh said:

Thank you for that. I was about to ask, well isn't it going to spend the next 12+ hours rebuilding the new drive without the ability to read from it? Reduced performance is fine with me.

I'm assuming I will also be able to write to the array while this new drive is being rebuilt?

Yes - the system will react as if the drive is present whether reading or writing.   The only caveat being that with a single parity drive the writes can not assume to be  'protected' until the rebuild process has completed so that the disk being rebuilt and parity are now fully in sync with each other.