Installing, configuring and running OCFS2 on Gentoo Linux


INSTALLING
==========
Step 1 - Inserting modules
--------------------------
Add 'ocfs2', 'configfs' to your /etc/modules.autoload.d/kernel-2.6 file:
# echo "ocfs2" >> /etc/modules.autoload.d/kernel-2.6
# echo "configfs" >> /etc/modules.d/autoload.d/kernel-2.6
# update-modules

Step 2 - Mounting the pseudo-filesystems 
----------------------------------------
add mountpoints for configfs and dlmfs to /etc/fstab
# echo "none /sys/kernel/config configfs defaults 0 0" >> /etc/fstab
# echo "none /dlm ocfs2_dlmfs defaults 0 0" >> /etc/fstab

Step 3 - Addding ocfs2 to default runlevel 
------------------------------------------
# rc-update add ocfs2 default 


CONFIGURING 
===========
Step 1 - Edit your cluster.conf
-------------------------------
Edit /etc/ocfs2/cluster.conf and add your nodes. One node can be a member 
of many cluster, so repeat the config for each node/cluster pair. In the case of
a multicluster node, "ip_port" must be different for every cluster.
You can also use ocfs2console for this task, if you compiled with USE=X.

Step 2 - Copy config to other nodes
-----------------------------------
Make sure that every node in cluster(s) has an identical config file.

Step 3 - Update /etc/conf.d/ocfs2
---------------------------------
Add names of cluster(s) in which this node belongs to the OCFS2_CLUSTERS list.

Also, if you're running firewall on your nodes, make sure you've read
"Firewall restrictions" below.

RUNNING 
=======

Notes about adding nodes while online
-------------------------
*DON'T* add nodes to /etc/ocfs2/cluster.conf while the cluster is online.
Use /sbin/o2cb_ctl instead, e.g.:

# /sbin/o2cb_ctl -C -n <node_name> -t node -a number=<node_number> \ 
  -a ip_address=<ip_address> -a ip_port=<port> -a cluster=<clustername>

If the complete cluster is down, you may add nodes to /etc/ocfs2/cluster.conf,
but make sure you end up with *SAME* cluster.conf on every node.

For a complete reference, check files in this directory
as well as http://oss.oracle.com/projects/ocfs2
You have been warned.

Also, if you're running a firewall on your nodes, make sure you've read the
following section.

Firewall restrictions
---------------------
Logically, allow all nodes to connect to each other via specified port(s). 
If you used 7777 as a port for communication, issue: 

# iptables -I INPUT 1 -m state --state ESTABLISHED,RELATED -j ACCEPT
# iptables -N OCFS2_NODES
# iptables -A OCFS2_NODES -s <node_ip_address> -j ACCEPT
(repeat former command for every node)
# iptables -A OCFS2_NODES -j DROP
# iptables -A INPUT -p tcp --dport 7777 -m state --state NEW -j OCFS2_NODES
# /etc/init.d/iptables save 

You should do this on every node.

KNOWN BUGS
==========
1. Init script does not have all the funtionality of the o2cb script
----------------------------------------------------------------
I know that, but o2cb script doesn't use "depend" and therefore its start 
can't be controlled inside runlevels. I had to rewrite major portions of it 
to make it Gentoo-friendly. o2cb is still available, and if you need 
additional functionality from /etc/init.d/ocfs2, file a bug report (see 
"Reporting Bugs" below).

2. Booting off the ocfs2 cluster doesn't work
---------------------------------------------
... or at least, isn't tested. If someone wants to play with it, I'd be 
happy to incorporate any ideas or experiences.

REPORTING BUGS
==============
Open a bug at http://bugs.gentoo.org and add laza@yu.net into the CC list.
If the problem is within my powers, I'll fix it, if not, I'll 
escalate it to ocfs2 developers.

---
05. Aug 2005. 
Lazar Obradovic