Adds docker-storage-setup example.

docs/base.rst

@@ -3,6 +3,58 @@ Cloud Base Image examples
 
 This chapter will contain various examples related to Cloud Base Image.
 
+How to do docker-storage-setup in Fedora 22 cloud image?
+--------------------------------------------------------
+
+docker-storage-setup helps to create a LVM thin pool, which can be then used by
+docker for storage of containers, and images. By starting docker, it
+automatically starts this service. We can also make sure that it uses a
+specific block device, and volume group. In this example I am running Fedora 22
+Cloud Base image on an Openstack environment, I added a new volume */dev/vdb*
+to the instance.
+
+::
+
+    # cat <<EOF > /etc/sysconfig/docker-storage-setup
+    DEVS=/dev/vdb
+    VG=docker-vg
+    EOF
+    # sudo docker-storage-setup
+      Volume group "vda1" not found
+      Cannot process volume group vda1
+    Checking that no-one is using this disk right now ... OK
+
+    Disk /dev/vdb: 5 GiB, 5379194880 bytes, 10506240 sectors
+    Units: sectors of 1 * 512 = 512 bytes
+    Sector size (logical/physical): 512 bytes / 512 bytes
+    I/O size (minimum/optimal): 512 bytes / 512 bytes
+    Disklabel type: dos
+    Disk identifier: 0xc8ed8872
+
+    Old situation:
+
+    >>> Script header accepted.
+    >>> Created a new DOS disklabel with disk identifier 0x39ca0d62.
+    Created a new partition 1 of type 'Linux LVM' and of size 5 GiB.
+    /dev/vdb2: 
+    New situation:
+
+    Device     Boot Start      End  Sectors Size Id Type
+    /dev/vdb1        2048 10506239 10504192   5G 8e Linux LVM
+
+    The partition table has been altered.
+    Calling ioctl() to re-read partition table.
+    Syncing disks.
+      Physical volume "/dev/vdb1" successfully created
+      Volume group "docker-vg" successfully created
+      Rounding up size to full physical extent 8.00 MiB
+      Logical volume "docker-poolmeta" created.
+      Logical volume "docker-pool" created.
+      WARNING: Converting logical volume docker-vg/docker-pool and docker-vg/docker-poolmeta to pool's data and metadata volumes.
+      THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.)
+      Converted docker-vg/docker-pool to thin pool.
+      Logical volume "docker-pool" changed
+
 How to build a network router and firewall with Fedora 22 and systemd-networkd?
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