Setup the environment - Build ceph and ceph-client

Here is a snippet from a script that I wrote that checks to see if
your system has all the packages and if not it installs them. If you
preffer installing them by hand below is a list.

packages_general=(git vim quilt);
packages_build=(autoconf automake autotools-dev debhelper libatomic-ops-dev
				libboost-dev libcrypto++-dev libcurl4-gnutls-dev libedit-dev
				libexpat1-dev libfcgi-dev libfuse-dev libgoogle-perftools-dev
				libgtkmm-2.4-dev libkeyutils-dev libtool pkg-config python
				python-dev python-pip python-support python-virtualenv uuid-dev
				cython libsnappy-dev libleveldb-dev libblkid-dev libudev-dev
				libnss3-dev libcurl4-nss-dev libaio-dev xfslibs-dev

				libboost-thread-dev libboost-random-dev libboost-regex-dev
				libboost-program-options-dev liblttng-ust-dev libbz2-dev);

Go to https://github.com/ceph/ and as you
see there will be more projects that the ceph community is working
on. At the moment, we are interested in ceph and ceph-client.


Just to make everything clean and easy I will describe my folder
structure. In my home directory I have an empty folder 'work' where
I want to place ceph derived things.

# it will take some time depending on the internet connection
cd ~/ceph
git clone https://github.com/ceph/ceph.git
git clone https://github.com/ceph/ceph-client

We will build ceph using Autotools and the below instructions can
also be found in ceph/README along other useful things such as
building ceph using cmake (if you prefer it that way).

There are two steps involved in building anything: configuring and
actually building it.

# get to the right directory
cd ~/work
cd ceph

# handle the configuration part
./do_autogen.sh -d3 

# now build ceph

make

or if you have multiple cores/threads it would be better to use

make -j $num_procs

where 'num_procs' is the number of processors of your system. What
it does is to specify the right level of conccurency and therefore speedup
your build. In my case it is: make -j4.


Now you should just go watch a movie, read a book or anything else...
because it may take a while.

If you browse a little bit the ceph-client folder you may discover
that ceph-client is actually a kernel source appended with anything
that the ceph project needs.

Now I should mention the fact that this step needs another package
installed, so:

sudo apt-get install libncurses5-dev  # in order to user ncurses headers

The first thing to do is to get to the right folder in order to
configure and build the kernel.

cd ~/work/ceph-client

Now is the moment to mention the fact that the only thing that
distinguishes this build from any other one is the right
configuration that can be achieved with the following steps.

Creates a default configuration file .config based
on your system architecture

make defconfig

Add the specific bits that ceph client is interested in, more
exactly CEPH_LIB, CEPH_LIB_PRETTYDEBUG and CEPH_FS.
'make menuconfig' is using ncurses in order to provide an interface
to the configuration process

make menuconfig # only accepted way of editing kernel conf file

It will show a window in the current terminal. If you type  '/' a
search window will appear. The next step is to search for the three
key words and just activate their config options by hitting the 'y'
button. Save and exit. After this in your .config file from the
ceph-client root folder is a fully functional configuration file.

Now lets build the kernel:

make -j4 # by this time you know why is there a '-j4' option