Migrate ZFS-* message descriptions (#49)

Prerequisite for changing the URLs in the command outputs from
zfsonlinux.org to openzfs.github.io/openzfs-docs/

Signed-off-by: Ryan Moeller <ryan@iXsystems.com>

docs/msg/ZFS-8000-14/index.rst

@@ -0,0 +1,82 @@
+..
+   CDDL HEADER START
+
+   The contents of this file are subject to the terms of the
+   Common Development and Distribution License (the "License").
+   You may not use this file except in compliance with the License.
+
+   You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+   or http://www.opensolaris.org/os/licensing.
+   See the License for the specific language governing permissions
+   and limitations under the License.
+
+   When distributing Covered Code, include this CDDL HEADER in each
+   file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+   If applicable, add the following below this CDDL HEADER, with the
+   fields enclosed by brackets "[]" replaced with your own identifying
+   information: Portions Copyright [yyyy] [name of copyright owner]
+
+   CDDL HEADER END
+
+   Portions Copyright 2007 Sun Microsystems, Inc.
+
+.. highlight:: none
+
+Message ID: ZFS-8000-14
+=======================
+
+Corrupt ZFS cache
+-----------------
+
++-------------------------+--------------------------------------+
+| **Type:**               | Error                                |
++-------------------------+--------------------------------------+
+| **Severity:**           | Critical                             |
++-------------------------+--------------------------------------+
+| **Description:**        | The ZFS cache file is corrupted.     |
++-------------------------+--------------------------------------+
+| **Automated Response:** | No automated response will be taken. |
++-------------------------+--------------------------------------+
+| **Impact:**             | ZFS filesystems are not available.   |
++-------------------------+--------------------------------------+
+
+.. rubric:: Suggested Action for System Administrator
+
+ZFS keeps a list of active pools on the filesystem to avoid having to
+scan all devices when the system is booted.  If this file is corrupted,
+then normally active pools will not be automatically opened.  The pools
+can be recovered using the ``zpool import`` command:
+
+::
+
+   # zpool import
+     pool: test
+       id: 12743384782310107047
+    state: ONLINE
+   action: The pool can be imported using its name or numeric identifier.
+   config:
+
+           test              ONLINE
+             sda9            ONLINE
+
+This will automatically scan ``/dev`` for any devices part of a pool.
+If devices have been made available in an alternate location, use the
+``-d`` option to ``zpool import`` to search for devices in a different
+directory.
+
+Once you have determined which pools are available for import, you
+can import the pool explicitly by specifying the name or numeric
+identifier:
+
+::
+
+   # zpool import test
+
+Alternately, you can import all available pools by specifying the ``-a``
+option.  Once a pool has been imported, the ZFS cache will be repaired
+so that the pool will appear normally in the future.
+
+.. rubric:: Details
+
+The Message ID: ``ZFS-8000-14`` indicates a corrupted ZFS cache file.
+Take the documented action to resolve the problem.