Adding drive to mirror

[Jon Telfer]

Hi,
I have an HP microserver with two WD red 3tb disks currently sitting mirrored.

Code:

[root@freenas ~]# zpool status keith																								
  pool: keith																													   
state: ONLINE																													 
status: Some supported features are not enabled on the pool. The pool can														   
		still be used, but some features are unavailable.																		   
action: Enable all features using 'zpool upgrade'. Once this is done,															   
		the pool may no longer be accessible by software that does not support													 
		the features. See zpool-features(7) for details.																			
  scan: resilvered 12K in 0h0m with 0 errors on Fri Jun 30 20:51:06 2017															
config:																															 
																																	
		NAME											STATE	 READ WRITE CKSUM												 
		keith										   ONLINE	   0	 0	 0												 
		  mirror-0									  ONLINE	   0	 0	 0												 
			gptid/cf3d2cc4-f02a-11e4-b765-3464a99aff78  ONLINE	   0	 0	 0												 
			gptid/cfa49fa7-f02a-11e4-b765-3464a99aff78  ONLINE	   0	 0	 0												 
																																	
errors: No known data errors																										
[root@freenas ~]#																											   

I have a third WD red 3tb disk which I'd like to add to the mirror. Though the third drive is visible in the gui, it doesn't appear to allow this unless I add a fourth drive to create a mirrored mirror. I can see command line options in example 4-5 here http://docs.oracle.com/cd/E19253-01/819-5461/6n7ht6qvl/index.html which look to do what I'm after.

System is recently upgraded to 11 which I think is behind the upgrade notes in the zpool status.

Is this a good idea? Am I going to break everything?

Thanks for any help.
Jon

 

[Ericloewe]

The GUI doesn't have support for manipulating mirror vdevs yet. You'd have to do it manually. Export the pool, import it in the CLI, do what needs to be done and export it and import it in the GUI.