ceph/README.FreeBSD

Last updated: 2017-04-08

The FreeBSD build will build most of the tools in Ceph.
Note that the (kernel) RBD dependent items will not work

I started looking into Ceph, because the HAST solution with CARP and 
ggate did not really do what I was looking for. But I'm aiming for 
running a Ceph storage cluster on storage nodes that are running ZFS.
In the end the cluster would be running bhyve on RBD disk that are stored in 
Ceph.

The FreeBSD build will build most of the tools in Ceph.
	
Progress from last report:
==========================

Most important change:
  -	A port is submitted: net/ceph-devel.

Other improvements:

	* A new ceph-devel update will be submitted in April

  -	Ceph-Fuse works, allowing to mount a CephFS on a FreeBSD system and do
	some work on it. 
  -	Ceph-disk prepare and activate work for FileStore on ZFS, allowing 
	easy creation of OSDs.
  -	RBD is actually buildable and can be used to manage RADOS BLOCK 
	DEVICEs.
  -	Most of the awkward dependencies on Linux-isms are deleted only
	/bin/bash is there to stay.

Getting the FreeBSD work on Ceph:
=================================

	pkg install net/ceph-devel

Or:
	cd "place to work on this"
	git clone https://github.com/wjwithagen/ceph.git
	cd ceph
	git checkout wip.FreeBSD

Building Ceph
=============
  - 	Go and start building
	  ./do_freebsd.sh
	
Parts not (yet) included:
=========================

 - KRBD
	 Kernel Rados Block Devices is implemented in the Linux kernel
	 And perhaps ggated could be used as a template since it does some of 
	 the same, other than just between 2 disks. And it has a userspace 
	 counterpart.
 - BlueStore.
	 FreeBSD and Linux have different AIO API, and that needs to be made 
	 compatible Next to that is there discussion in FreeBSD about 
	 aio_cancel not working for all devicetypes
 - CephFS as native filesystem
	 (Ceph-fuse does work.)
	 Cython tries to access an internal field in dirent which does not 
	 compile
Build Prerequisites
===================

	Compiling and building Ceph is tested on 12-CURRENT, but I guess/expect 
	11-RELEASE will also work. And Clang is at 3.8.0.
	It uses the CLANG toolset that is available, 3.7 is no longer tested, 
	but was working when that was with 11-CURRENT. 
	Clang 3.4 (on 10.2-STABLE) does not have all required capabilities to 
	compile everything

The following setup will get things running for FreeBSD:
	
	This all require root privilidges.

 -	Install bash and link it in /bin
	sudo pkg install bash
	sudo ln -s /usr/local/bin/bash /bin/bash

Getting the FreeBSD work on Ceph:
=================================

 - 	cd "place to work on this"
	git clone https://github.com/wjwithagen/ceph.git
	cd ceph
	git checkout wip.FreeBSD.201702

Building Ceph
=============
 - 	Go and start building
	./do_freebsd.sh
	
Parts not (yet) included:
=========================

 -	KRBD
	Kernel Rados Block Devices is implemented in the Linux kernel
	It seems that there used to be a userspace implementation first.
	And perhaps ggated could be used as a template since it does some of 
	the same, other than just between 2 disks. And it has a userspace 
	counterpart.
 -	BlueStore.
	FreeBSD and Linux have different AIO API, and that needs to be made 
	compatible Next to that is there discussion in FreeBSD about 
	aio_cancel not working for all devicetypes
 -	CephFS
	Cython tries to access an internal field in dirent which does not 
	compile

Tests that verify the correct working of the above are also excluded 
from the testset

Tests not (yet) include:
=======================

 -  	None, although some test can fail if running tests in parallel and there is
    	not enough swap. Then tests will start to fail in strange ways.
 
Task to do:
===========
 -	Build an automated test platform that will build ceph/master on 
	FreeBSD and report the results back to the Ceph developers. This will 
	increase the maintainability of the FreeBSD side of things. 
	Developers are signalled that they are using Linux-isms that will not
	compile/run on FreeBSD Ceph has several projects for this: Jenkins, 
	teuthology, pulpito, ...
	But even just a while { compile } loop and report the build data on a 
	static webpage would do for starters.

 -	Run integration tests to see if the FreeBSD daemons will work with a 
	Linux Ceph platform.

 -	Compile and test the user space RBD (Rados Block Device).

 -	Investigate and see if an in-kernel RBD device could be developed a la 
	'ggate'

 -	Investigate the keystore, which could be kernel embedded on Linux an 
	currently prevents building Cephfs and some other parts.

 -	Scheduler information is not used atm, because the schedulers work 
	rather different. But at a certain point in time, this would need some 
	attention:
	in: ./src/common/Thread.cc

 -	Improve the FreeBSD /etc/rc.d initscripts in the Ceph stack. Both 
	for testing, but mainly for running Ceph on production machines.
	Work on ceph-disk and ceph-deploy to make it more FreeBSD and ZFS 
	compatible. 

 -	Build test-cluster and start running some of the teuthology integration 
	tests on these.
	Teuthology want to build its own libvirt and that does not quite work
	with all the packages FreeBSD already has in place. Lots of minute 
	details to figure out

 -	Design a virtual disk implementation that can be used with behyve and 
	attached to an RBD image.