oem@hp ~ $ sudo zpool status
  pool: sg4t
 state: DEGRADED
status: One or more devices is currently being resilvered.  The pool will
	continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
  scan: resilver in progress since Sun May  7 02:28:22 2017
    1.04G scanned out of 2.35T at 13.7M/s, 50h5m to go
    1.03G resilvered, 0.04% done
config:

	NAME                           STATE     READ WRITE CKSUM
	sg4t                           DEGRADED     0     0     0
	  mirror-0                     DEGRADED     0     0     0
	    sdd                        ONLINE       0     0     0
	    replacing-1                OFFLINE      0     0     0
	      /media/loop0/4tb_sparse  OFFLINE      0     0     0
	      sda                      ONLINE       0     0     0  (resilvering)
	logs
	  sdb3                         ONLINE       0     0     0

errors: No known data errors