I have a Norco case. I have a slot reserved for where I preclear drives. After I preclear a drive, can I remove and put another drive in the slot without shutting down the server?

Yes, as long as the controller connected to that slot supports hot swap.

You will, however, have to stop the array. You should do that before removing a disk, and there would be no benefit from trying it with the array running since you can't assign the new disk with the array started anyway.

 

NVM, I see you weren't talking about an array disk

It's an LSI Logic SAS 9207-8i Storage Controller LSI00301

You can, before doing better to disable it, it also usually powers off the disk:

 

echo 1 > /sys/block/sdX/device/delete

 

5 minutes ago, johnnie.black said:

You can, before doing better to disable it, it also usually powers off the disk:

 

echo 1 > /sys/block/sdX/device/delete

 

Thanks, it worked perfectly. I saw it removed from the unassigned devices. I took it out and put the new drive it and after I refreshed the screen I saw the new drive listed. I had to press a button for the clear starts in order to access the preclear button. I guess the addon didn't notice it's a different drive.