If I remove a full drive that is suspected to be failing, what happens to the data?

[arretx]

I have a 6-drive array in a hot-swap configuration, and the parity drive is 8TB.  

 

One of the array drives is 500GB and the rest are 8TB.

 

Disk 1 is an 8TB drive that was shucked from a seagate external hard drive.  It's old and there's a "thumbs down" on it under the "SMART" column on the dashboard.

 

I have a new 8TB Ironwolf drive sitting on the shelf.

 

If I were to simply pull the drive from the hot swap cage and plug in the new one, will I lose any of the data that was on the disk I pulled?

[JonathanM]

1st, Unraid does not support hot replacement while the array is running. You must at least stop the array to select the replacement drive, and depending on the disk controller, you may need to power down to get the new drive properly detected. Just wanted to get that out of the way, as it sounded like you intended to hot swap while the array was running.

 

If parity is in sync, then the removed drive will be completely and accurately emulated by all the rest of the drives, and you can rebuild that content to the new drive. However, if parity is not correct, or any one of the array drives doesn't return good data, then the rebuild will be corrupt.

 

A parity check is the only way to know for sure that parity is in sync, so the more recent your last parity check with zero errors, the more confident you can be.

[trurl]

53 minutes ago, arretx said:

It's old and there's a "thumbs down" on it under the "SMART" column on the dashboard.

That doesn't tell us enough to know if it should be replaced. Might just be connection problem, even old connection problem. If you mouseover it will show the reason.

 

Attach diagnostics to your NEXT post in this thread and we can see what the warning is about and give better advice on how you should proceed.