# [FreeNAS] Problem with zfs pool



## ManuelW (Apr 12, 2012)

Hey guys,

I've got a problem with my zfs pool after a reboot of the machine.


```
freenas:~# zpool status -x
  pool: DatenPool
state: UNAVAIL
status: One or more devices could not be opened.  There are insufficient
   replicas for the pool to continue functioning.
action: Attach the missing device and online it using 'zpool online'.
   see: http://www.sun.com/msg/ZFS-8000-3C
scan: none requested
config:

   NAME                   STATE     READ WRITE CKSUM
   DatenPool              UNAVAIL      0     0     0
     ada0                 ONLINE       0     0     0
     8487461287165642183  UNAVAIL      0     0     0  was /dev/ada2
```

but ada2 is avail and online

```
crw-r-----   1 root  operator    0,  99 Apr 12 19:14 ada2
```

What can I do to bring the pool back online?


----------



## Sebulon (Apr 13, 2012)

ManuelW said:
			
		

> What can I do to bring the pool back online?



Sadly, not that much. Your chances are slim to none IÂ´m afraid, because of the way the pool is set up without any redundancy. Your only shot is to:
`# zpool online DatenPool ada2`
And pray And even if that works, you should still scrub the pool afterwards and will probably have lots of damage. If it fails, I hope you have backups to restore from.

Reading material for ZFS drivers license:
First off, from the good book
Then the wiki
And finally, the admin guide for reference.

/Sebulon


----------



## ManuelW (Apr 13, 2012)

Sebulon said:
			
		

> `# zpool online DatenPool ada2`




```
cannot open 'DatenPool': pool is unavailable
```

Hmm 
*B*ut the disks are untouched. *T*here only was "offline" and then back online without damage or errors or something else. I don*'*t understand why the tank won't work, if the disk is back again.


----------

