Device Removed by Administrator in ZPOOL?

[Kaya Saman]

Hi,

I'm running FreeBSD 10.0 x64 on a Xeon E5 based system with 8GB RAM.


Checking the ZPOOL status I saw one of my drives has been offlined... 
the exact error is this:

# zpool status -v
   pool: ZPOOL_2
  state: DEGRADED
status: One or more devices has been removed by the administrator.
     Sufficient replicas exist for the pool to continue functioning in a
     degraded state.
action: Online the device using 'zpool online' or replace the device with
     'zpool replace'.
   scan: scrub repaired 0 in 9h3m with 0 errors on Sat Apr  5 03:46:55 2014
config:

     NAME                      STATE     READ WRITE CKSUM
     ZPOOL_2                   DEGRADED     0     0     0
       raidz2-0                DEGRADED     0     0     0
         da0                   ONLINE       0     0     0
         14870388343127772554  REMOVED      0     0     0  was /dev/da1
         da2                   ONLINE       0     0     0
         da3                   ONLINE       0     0     0
         da4                   ONLINE       0     0     0


I think this is due to a dead disk however, I'm not certain which is why 
I wanted to ask here as I didn't remove the drive at all..... rather 
then some kind of OS/ZFS error.


The drives are 2TB WD Green drives all connected to an LSI HBA; 
everything is still under warranty so no big issue there and I have 
external backups too so I'm not really that worried, I'm just trying to 
work out what's going on.


Are my suspicions correct or should I simply try to reboot the system 
and see if the drive comes back online?


Regards,


Kaya