Add 2014 FOSDEM talk.

[libguestfs-talks.git] / 2014-fosdem / notes.txt

diff --git a/2014-fosdem/notes.txt b/2014-fosdem/notes.txt
new file mode 100644 (file)
index 0000000..f746e83
--- /dev/null
+++ b/2014-fosdem/notes.txt
@@ -0,0 +1,119 @@
+FOSDEM lightning talk
+Sunday 2nd Feb 2014, 16:00, H.2215 Ferrer
+https://fosdem.org/2014/schedule/event/libguestfs/
+
+Advanced disk image management with libguestfs
+libguestfs, virt-builder, virt-sparsify, virt-sysprep
+
+----------------------------------------------------------------------
+
+
+Good afternoon.  Today I'm going to talk about libguestfs
+with is a suite of tools for looking inside and modifying
+virtual machine disk images.
+
+
+virt-builder
+------------
+
+First off, a new tool that we've written to create virtual machines.
+
+[ Show the builder.sh script ]
+[ Run the builder.sh script ]
+
+I'll come back to this script at the end of the talk.
+
+virt-builder can:
+
+ - output raw, qcow2 and other formats
+ - resize using [virt-resize]
+ - write a random seed
+ - set a hostname
+ - edit configuration files
+ - install packages
+ - run custom scripts
+     * at build time
+     * or at first boot
+
+Libguestfs can safely and securely inspect and modify disk
+images without needing root.
+
+Virt-builder doesn't install guests from scratch.  Instead it
+takes clean, cryptographically signed, compressed templates and uses
+libguestfs to customize them.
+
+
+
+Preparing the templates
+-----------------------
+
+virt-builder comes with a handful of templates.
+
+You can also prepare your own.  
+
+Over the years we have come up with a good way
+to prepare and distribute reasonably small templates
+
+    virt-install     (or Oz)
+        v
+    virt-sysprep
+        v
+    virt-sparsify
+        v
+       xz
+
+virt-install runs a regular OS install, using anaconda,
+debian-installer, etc.  You can automate this completely
+using kickstart or preseed.
+
+virt-sysprep unconfigures the guest.  Using libguestfs it
+removes SSH host keys, log files, network configuration,
+user accounts and so on.
+
+virt-sparsify
+-------------
+
+virt-sparsify uses libguestfs to make guests sparse a.k.a.
+thin-provisioned.
+
+It looks for unused space:
+
+ - in filesystems
+
+ - in LVM physical volumes
+
+ - swap partitions
+
+Including non-zeroed, but unused blocks.
+
+It converts that to sparseness in the host file.
+
+
+xz
+--
+
+Finally xz compresses the template.  We like xz for several reasons:
+
+ - nearly best in class compression
+
+ - preserves sparseness
+
+ - compressed files can be random accessed  [nbdkit]
+
+ - virt-builder includes parallel uncompress
+
+
+Results
+-------
+
+               disk apparent final
+CirrOS 0.3.1     39       18    11 MB
+Debian 7       4096      719   142 MB
+Fedora 20      6144      826   174 MB
+Ubuntu 13.10   4096     1019   187 MB
+
+
+[At the end of the talk, show the progress of the builder script.]
+
+
+* libguestfs resources and other tools