====== FreeNAS - Replace a Drive ======

The GUI informs that the zpool is degraded.

----

===== List the Pools =====

<code bash>
zpool list
</code>

returns:

<code bash>
NAME           SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
Pool1         43.5T  35.6T  7.94T        -         -    10%    81%  1.00x    ONLINE  /mnt
freenas-boot   216G  5.08G   211G        -         -     0%     2%  1.00x    ONLINE  -
</code>

----

===== Check the status of the Pool =====

<code bash>
zpool status Pool1
</code>

returns:

<code bash>
  pool: Pool1
 state: DEGRADED
status: One or more devices has experienced an unrecoverable error.  An
    attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
    using 'zpool clear' or replace the device with 'zpool replace'.
   see: http://illumos.org/msg/ZFS-8000-9P
config:

	NAME                                            STATE     READ WRITE CKSUM
	Pool1                                           ONLINE       0     0     0
	  raidz1-0                                      ONLINE       0     0     0
	    gptid/2d35e96c-b611-11ea-be33-00d861fcb7d8  ONLINE       0     0     0
	    gptid/2d41dcbd-b611-11ea-be33-00d861fcb7d8  ONLINE       0     0    40  too many errors
	    gptid/2ddb5cb2-b611-11ea-be33-00d861fcb7d8  ONLINE       0     0     0

errors: No known data errors
</code>

<WRAP info>
**NOTE:**  This shows the disks within the Pool.

It also shows that device 2d41dcbd-b611-11ea-be33-00d861fcb7d8 has errors.
</WRAP>

----

===== Determine the actual disk connected to that device =====

<code bash>
glabel status | grep 2d41dcbd
</code>

returns:

<code bash>
gptid/2d41dcbd-b611-11ea-be33-00d861fcb7d8     N/A  ada3p2
</code>

<WRAP info>
**NOTE:**  This shows that the disk is **/dev/ada3**
</WRAP>

----

===== Determine the Serial Number of the Disk =====

<code bash>
sudo camcontrol identify ada3 | grep serial
</code>

returns:

<code bash>
serial number         ZL21DEPA
</code>

----

  * Power off the system.
  * Pull the failed drive and replace it with a new drive.
  * Reboot.
  * Navigate back and find the OFFLINE disk.
  * <WRAP info>
**NOTE:**  It will be the one with a series of numbers rather than a device name, and click the **Replace** button and select the new device (should be the only one on the list).

Since this drive is entirely new and unpartitioned, you'll need to force the replacement.

After that, it's just a matter of sitting back while the volume performs the resilver operation.
</WRAP>

----

===== Estimate how long it will take to resilver =====

<code bash>
zpool status -v Pool1
</code>

returns:

<code bash>
  pool: Pool1
 state: ONLINE
tatus: 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 Wed Jan 12 12:34:19 2014
        16.3G scanned out of 15.85T at 592M/s, 8h12m to go
        1.4G resilvered, 9.82% done
config:

	NAME                                            STATE     READ WRITE CKSUM
	Pool1                                           ONLINE       0     0     0
	  raidz1-0                                      ONLINE       0     0     0
	    gptid/2d35e96c-b611-11ea-be33-00d861fcb7d8  ONLINE       0     0     0
	    gptid/11111111-b611-11ea-be33-00d861fcb7d8  ONLINE       0     0     0  (resilvering)
	    gptid/2ddb5cb2-b611-11ea-be33-00d861fcb7d8  ONLINE       0     0     0

errors: No known data errors
</code>

<WRAP info>
**NOTE:**  Notice the resilvered disk has a new id, starting 11111111, which will differ as it is a different disk.
</WRAP>

----