So I got a red dot on disk 9. Is there anyway to remove disk 9 and never use it, also building parity back up?

 

You don't care about the data on disk 9?  It is possible to do what you are asking, but you will lose all data on disk 9 by doing so.  You will also put the rest of the data in your array at risk of a drive failure for roughly 16 hours (or more).

 

If you are sure that is what you want to do, then you will want to stop your array, unassign disk9 on the devices page, start the array, and finally run the 'initconfig' command.  This command will wipe your current parity data (so your array will be unprotected until a parity sync and subsequent parity check are completed).  In unRAID 4.7 you must run the command from telnet or the system console.  In unRAID 5.0 beta you can run it from the web GUI under the utilities tab.  Next, start your array - this will kick off a parity sync based only on the disks currently assigned (all of your data disks except for disk9).  Once the parity sync completes, run a parity check.  Once the parity check completes without error, you are in the clear.

 

There is also a method to remove disk9 without losing parity protection, but it is much more involved.  Since you already have a failed disk, I'm not sure if it will work or not.  Here's the method: link.  You might want to PM bjp999 and direct him to this thread if you have questions about that method.