docs: Update the "supported images" section

snf-image-creator can work with different image formats nowadays.

docs/overview.rst

@@ -2,8 +2,12 @@ Overview
 ^^^^^^^^
 
 snf-image-creator is a simple command-line tool for creating OS images. The
-original media the image is created from, can be a block device, a regular
-file that represents a hard disk or the host system itself.
+original media, the image is created from, can be:
+
+ * a block device, representing a hard disk
+ * a disk image file, representing a hard disk (supports all image file formats
+   supported by QEMU)
+ * the host system itself
 
 Snapshotting
 ============

docs/usage.rst

@@ -318,102 +318,17 @@ Choosing *YES* will create and upload the image to your cloud account.
 Working with different image formats
 ====================================
 
-*snf-image-creator* works on raw image files. If you have an image file with a
-different image format you can either convert it to raw using
-*qemu-img convert* command or use the *blktap* toolkit that provides a
-user-level disk I/O interface and use the exposed *tapdev* block device as
-input on *snf-image-creator*.
+*snf-image-creator* is able to work with the most popular disk image formats.
+It has been successfully tested with:
 
-Converting images to raw
-------------------------
-
-Converting between images with *qemu-img convert* is generally straightforward.
-All you need to provide is the output format (*-O raw*) and an output filename.
-You may use the *-f* option to define the input format, but in most cases this
-is guessed automatically. The table below shows a list of supported image
-formats and the equivalent argument you may pass to the *-f* flag.
-
-+--------------------------+-----------+
-|Image Format              |-f argument|
-+==========================+===========+
-|qcow2 (QEMU Copy On Write)|qcow2      |
-+--------------------------+-----------+
-|VHD (Mircosoft Hyper-V)   |vpc        |
-+--------------------------+-----------+
-|VMDK (VMware)             |vmdk       |
-+--------------------------+-----------+
-
-With the following commands we demonstrate how to download and convert an
-official Ubuntu 14.04 *qcow2* image to raw:
-
-.. code-block:: console
-
-   $ wget http://uec-images.ubuntu.com/trusty/current/trusty-server-cloudimg-amd64-disk1.img
-   $ qemu-img convert -f qcow2 -O raw trusty-server-cloudimg-amd64-disk1.img ubuntu.raw
-
-Working on .vhd disk images using blktap/tapdisk
-------------------------------------------------
-
-If the source image format is *Microsoft VHD* [#f1]_, we can use blktap/tapdisk
-to connect it to a block device and use this block device as input in
-*snf-image-creator* without having to convert the image to raw format.
-
-Assuming that you work on a recent Debian GNU/Linux, you can install the
-needed tools by giving the following command:
-
-.. code-block:: console
-
-   # apt-get install blktap-utils
-   # modprobe blktap
-
-Please refer to your distribution's documentation on how to install the blktap
-user-space tools and the corresponding kernel module.
-
-After you have successfully installed blktap, do the following to attack the
-source image (*/tmp/Centos-6.2-x86_64-minimal-dist.vhd*) to a block device:
-
-Allocate a minor number in the kernel:
-
-.. code-block:: console
-
-   # tap-ctl allocate
-   /dev/xen/blktap-2/tapdev0
-
-Then, spawn a tapdisk process:
-
-.. code-block:: console
-
-   # tap-ctl spawn
-   tapdisk spawned with pid 14879
-
-Now, attach them together:
-
-.. code-block:: console
-
-   # tap-ctl attach -m 0 -p 14879
-
-And finally, open the VHD image:
-
-.. code-block:: console
-
-   # tap-clt open -m 0 -p 14879 -a vhd:/tmp/Centos-6.2-x86_64-minimal-dist.vhd
-
-Now you can open the associated block device with *snf-image-creator* like
-this:
-
-.. code-block:: console
-
-   # snf-image-creator /dev/xen/blktap-2/tapdev
-
-When done, you may release the allocated resources by giving the following
-commands:
-
-.. code-block:: console
-
-   # tap-ctl close -m 0 -p 14879
-   # tap-ctl detach -m 0 -p 14879
-   # tap-ctl free -m 0
+* Raw disk images
+* VMDK (VMware)
+* VHD (Microsoft Hyper-V)
+* VDI (VirtualBox)
+* qcow2 (QEMU)
 
+It can support any image format QEMU supports as long as it represents a
+bootable hard drive.
 
 Limitations
 ===========