Setting up CTDB on OCFS2 and VMs ...

[Richard Sharpe]

On Sat, Dec 6, 2014 at 2:58 AM, Rowland Penny <repenny241155 at gmail.com> wrote:
> On 04/12/14 18:08, Richard Sharpe wrote:
>>
>> Hi folks,
>>
>> Here are the steps I used, as far as I can remember them. Please
>> excuse any mistakes and be prepared to think for yourself when
>> following them.
>>
>> 1. Create two VirtualBox VMs with enough memory and disk for your
>> Linux Distro. I used CentOS 6.6 with 4GB and 20GB. (I actually
>> installed CentOS 6.3 and upgraded because I had the ISO handy.) You
>> will also need an extra interface on each VM for the clustering
>> private network. I set them to an internal type.
>>
>> 2. Because you will need a shared disk, create one:
>>
>> vboxmanage createhd --filename ~/VirtualBox\ VMs/SharedHD1 --size
>> 10240 --variant Fixed --format VDI # Creates a 10GB fixed sized disk
>> vboxmanage modifyhd 22ae1fcc-fda7-4e42-be9f-3b8bd7fc0c0e --type
>> shareable # Make it shareable.
>>
>> Note, for that second command use the UUID for your disk which you can
>> find with:
>>
>> vboxmanage list hdds --brief
>>
>> Also, use the GUI to add the shared disk to both VMs.
>>
>> 3. Install the OS on each of the VMs.
>>
>> 4. I installed a bunch of clustering RPMs next:
>>
>> yum install openais corosync pacemaker-libs pacemaker-libs-devel gcc
>> corosync-devel openais-devel rpm-build e2fsprogs-devel libuuid-devel
>> git pygtk2 python-devel readline-devel clusterlib-devel redhat-lsb
>> sqlite-devel gnutls-devel byacc flex nss-devel
>>
>> It is not clear to me that openais was needed, for example
>>
>> 5. Next I installed Oracles UEK and ocfs2-tools
>>
>> wget http://public-yum.oracle.com/public-yum-ol6.repo /etc/yum.repos.d
>> wget http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 -O
>> /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
>> yum install kernel-uek kernel-uek-devel
>> yum install ocfs2-tools
>> yum install openaislib-devel corosync-devel # It is not clear that I
>> needed to install the first
>>
>> echo 'KERNEL=="ocfs2_control", NAME="misc/ocfs2_control", MODE="0660"'
>>>
>>> /etc/udev/rules.d/99-ocfs2_control.rules
>>
>> reboot # on each
>>
>> 6. Configure cman and pacemaker
>>
>> # configure corosync first
>> cp /etc/corosync/corosync.conf.example /etc/corosync/corosync.conf
>>
>> # Make sure that bindnetaddr is defined and points to your private
>> interface. I set it to 192.168.122.0
>>
>> # Make sure that the mcastaddr is defined. I used 239.255.1.1
>> # make sure that the mcastport is defined. I used 5405
>>
>> # Copy that file to the other node.
>> scp /etc/corosync/corosync.conf root at 172.16.170.6:/etc/corosync
>>
>> /etc/init.d/pacemaker stop  # Stop these in case they were running
>> /etc/init.d/corosync stop # Same here
>>
>> yum install ccs pcs
>>
>> # Create a cluster
>>
>> ccs -f /etc/cluster/cluster.conf --createcluster ctdbdemo
>> ccs -f /etc/cluster/cluster.conf --addnode ocfs2-1
>> ccs -f /etc/cluster/cluster.conf --addnode ocfs2-2
>> ccs -f /etc/cluster/cluster.conf --addfencedev pcmk agent=fence_pcmk
>> ccs -f /etc/cluster/cluster.conf --addmethod pcmk-redirect ocfs2-1
>> ccs -f /etc/cluster/cluster.conf --addmethod pcmk-redirect ocfs2-2
>> ccs -f /etc/cluster/cluster.conf --addfenceinst pcmk ocfs2-1
>> pcmk-redirect port=ocfs2-1
>> ccs -f /etc/cluster/cluster.conf --addfenceinst pcmk ocfs2-2
>> pcmk-redirect port=ocfs2-2
>>
>> # Copy the cluster config file to the other node:
>> scp /etc/cluster/cluster.conf root at 172.16.170.6:/etc/cluster
>>
>> #Now turn off NetworkManager:
>> chkconfig NetworkManager off
>> service NetworkManager stop
>>
>> # now start the cluster
>> service cman start
>> pcs property set stonith-enabled=false
>> service pacemaker start
>>
>> # Also start it on the other node(s).
>>
>> # Now check the status:
>>      [root at ocfs2-1 ~]# crm_mon -1
>>      Last updated: Thu Dec  4 09:40:16 2014
>>      Last change: Tue Dec  2 10:12:50 2014
>>      Stack: cman
>>      Current DC: ocfs2-2 - partition with quorum
>>      Version: 1.1.11-97629de
>>      2 Nodes configured
>>      0 Resources configured
>>
>>
>>      Online: [ ocfs2-1 ocfs2-2 ]
>>
>> If you do not see all the other nodes online, then you have to debug
>> the problem.
>>
>> These are essentially the steps from here:
>> http://clusterlabs.org/quickstart-redhat.html
>>
>> 7. Configure the Oracle cluster
>>
>> o2cb add-cluster ctdbdemo
>> o2cb add-node --ip 192.168.122.10 --port --number 1 ctdbdemo ocfs2-1
>> o2cb add-node --ip 192.168.122.10 --port 7777 --number 1 ctdbdemo ocfs2-1
>> o2cb add-node --ip 192.168.122.11 --port 7777 --number 2 ctdbdemo ocfs2-2
>>
>> service o2cb configure # This step will fail claiming that it can't
>> find /sbin/ocfs2_controld.cman
>> #
>> # However, it does the important stuff.
>> #
>> # NOTE, during the configuration steps you MUST SELECT cman AS THE
>> CLUSTER STACK!
>> #
>>
>> 8. Find and install the ocfs2-tools git repos
>>
>> git clone git://oss.oracle.com/git/ocfs2-tools.git ocfs2-tools
>>
>> # install stuff needed
>> yum install libaio libaio-devel
>> yum install pacemaker-libs-devel
>>
>> # Now build
>> cd ocfs2-tools
>> ./configure
>> make
>>
>> # This will likely fail. If it first fails complaining about
>> xml/tree.h then you can do the following:
>> CPPFLAGS='-I/usr/include/libxml2' ./configure
>> make
>>
>> # It might complain again complaining about some AIS include files that
>> are no
>> # longer in the packages installed. That is OK. It should have built
>> ocfs2_controld.cman,
>> # so copy it where it needs to be:
>>
>> cp ocfs2_controld.cman /usr/sbin/
>> scp ocfs2_controld.cman root at 172.16.170.6:/usr/sbin/
>>
>> # Now stop those two you started and start everything:
>>
>> service pacemaker stop
>> service cman stop
>>
>> service cman start
>> service o2cb start
>> service pacemaker start
>>
>> 8. Create the shared shared file system on one node:
>>
>> mkfs.ocfs2 -L CTDBdemocommon --cluster-name ctdbdemo --cluster-stack
>> ocfs2 -N 4 /dev/sdb
>>
>> 9. Mount it on both and ensure that you can create files/dirs on one
>> node and see them on the other node.
>>
>> 10. Install ctdb and samba
>>
>> 11. Configure samba for the domain you want to join
>>
>> # Make sure you have clustering = yes and the other things you need.
>>
>> 12. Configure ctdb (/etc/sysconfig/ctdb) and make sure that you disable
>> winbindd
>>
>> 13. Start ctdb on all nodes
>>
>> # You must have ctdb started so that the secrets file will get distributed
>>
>> 14. join the domain
>>
>> 15. Enable winbindd in the ctdb config
>>
>> 16. Restart ctdb on all nodes
>>
>> At this point you should be done. The steps you need might vary.
>>
>> I have limited time to help you with this.
>>
>
> OK, I have followed Richards 'howto' but using Debian 7.7 instead of Centos,
> I also used the standard Debian kernel. I have got up to step 9, after a bit
> of a battle and it all started so well. :-)
>
> Most of the required packages are available from the repos:
>
> apt-get install openais corosync pacemaker cman ocfs2-tools-cman
> ocfs2-tools-pacemaker
>
> Unfortunately, it turned out that pacemaker is not built to use the cman
> stack, so I had to rebuild it
>
> Next problem, ccs and pcs are not available, so I had to download & build
> them, though even this was not without problems, ccs put
> 'empty_cluster.conf' in the wrong place and pcs is hardwired to use
> /usr/libexec
>
> Next problem 'o2cb' appears to be called 'o2cb_ctl' on Debian.
>
> Started cman, o2cb and pacemaker (first time round, this is where I found
> that pacemaker wouldn't work with cman)
>
> I then created the shared shared file system and mounted it on both nodes

OK, looks like you got the real stuff done.

> At this point I have a shared cluster, but in a way that I cannot see any
> sane sysadmin using. Most of the software is heavily modified or not
> available from the distros repos. I am going to have to stop and think about
> this and see if there is a Debian way of doing this, without modifying
> anything or using anything that is not available from a repo.

Indeed, I cannot imagine anyone using the approach I used for
production as well. Having stuff that needs to be rebuilt is not a
good idea, and it would be useful to get a minimal complete set of
RPMs together and fix ocfs2-tools so that the correct things are there
and the build works out what is needed.

However, I only currently need the OCFS2 setup for testing purposes
while we get our file system supporting FCNTL locks and so I have a
reference to work with.

Not sure if I have the time to fix anything.

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)