Doc how to add a hot spare.

Ticket: #27215

userguide/storage.rst

@@ -234,7 +234,7 @@ them in production.
 
 .. _Adding Cache or Log Devices:
 
-Adding Cache or LOG Devices
+Adding Cache or Log Devices
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 :ref:`Pools` can be used either during or after pool creation to add an
@@ -250,9 +250,39 @@ To add a device during pool creation, click the :guilabel:`Add Cache` or
 
 To add a device to an existing pool, click the pool's name then the
 :guilabel:`Standard Volume Operations` (gear) icon and select
-:guilabel:`Extend`. Click the :guilabel`Confirm` checkbox and click
+:guilabel:`Extend`. Click the :guilabel:`Confirm` checkbox and click
 :guilabel:`Ok` to bypass the warning message. This will reopen the pool
-creation screen but with the pool name displayed as read-only.
+creation screen described in the previous sentence, but with the pool name
+displayed as read-only.
+
+.. index:: Hot Spares, Spares
+.. _Adding Spare Devices:
+
+Adding Spare Devices
+~~~~~~~~~~~~~~~~~~~~
+
+ZFS provides the ability to have "hot" *spares*. These are drives that
+are connected to a pool, but not in use. If the pool experiences
+the failure of a data drive, the system uses the hot spare as a
+temporary replacement. If the failed drive is replaced with a new
+drive, the hot spare drive is no longer needed and reverts to being a
+hot spare. If the failed drive is instead removed from the pool, the
+spare is promoted to a full member of the pool.
+
+Hot spares can be added to a pool during or after creation. On
+%brand%, hot spare actions are implemented by
+`zfsd(8) <https://www.freebsd.org/cgi/man.cgi?query=zfsd>`__.
+
+To add a spare during pool creation, click the :guilabel:`Add Spare`.
+button. Check the box for the disk to use in :guilabel:`Available Disks`
+and use the left arrow to add it to the :guilabel:`Spare VDev` section.
+
+To add a device to an existing pool, click the pool's name then the
+:guilabel:`Standard Volume Operations` (gear) icon and select
+:guilabel:`Extend`. Click the :guilabel:`Confirm` checkbox and click
+:guilabel:`Ok` to bypass the warning message. This will reopen the pool
+creation screen described in the previous sentence, but with the pool name
+displayed as read-only.
 
 .. _Extending a Pool:
 
@@ -1593,25 +1623,6 @@ drive before replacing the next drive. After all the drives are
 replaced and the final resilver completes, the added space will appear
 in the pool.
 
-
-.. index:: Hot Spares, Spares
-.. _Hot Spares:
-
-Hot Spares
-~~~~~~~~~~
-
-ZFS provides the ability to have "hot" *spares*. These are drives that
-are connected to a pool, but not in use. If the pool experiences
-the failure of a data drive, the system uses the hot spare as a
-temporary replacement. If the failed drive is replaced with a new
-drive, the hot spare drive is no longer needed and reverts to being a
-hot spare. If the failed drive is instead removed from the pool, the
-spare is promoted to a full member of the pool.
-
-Hot spares can be added to a pool during or after creation. On
-%brand%, hot spare actions are implemented by
-`zfsd(8) <https://www.freebsd.org/cgi/man.cgi?query=zfsd>`__.
-
 .. index:: Snapshots
 .. _Snapshots: