I have setup a 3 node SLES 11 SP1 High Availability Extension cluster as
server1 and server2 are in our main datacenter and attached to shared
storage (formatted ocfs2) on our Compellent SAN. The name of the block
device for the shared storage is:
/dev/disk/by-id/scsi-vol01 (using multipath user friendly names).
This disk is mounted at /srv/www on both.
server3 is at a remote colo facility, and is attached to another
Compellent SAN, with a disk on that side mounted at /srv/www
Since I can’t do a 3-way active/active/active config, I’m going to use
rsync to sync the contents of /srv/www from server1 to server3 at the
Anyway, my question/request for suggestions is this:
I have followed the recommended steps for configuring ocfs/dlm,
etc…in Pacemaker as follows:
cib new stack-glue
configure primitive dlm ocf:pacemaker:controld op monitor
configure clone dlm-clone dlm meta globally-unique=false
cib commit stack-glue
cib new oracle-glue
configure primitive o2cb ocf:ocfs2:o2cb op monitor interval=120s
configure clone o2cb-clone o2cb meta globally-unique=false
configure colocation o2cb-with-dlm INFINITY: o2cb-clone dlm-clone
configure order start-o2cb-after-dlm mandatory: dlm-clone o2cb-clone
cib commit oracle-glue
The next step is:
configure primitive fs ocf:heartbeat:Filesystem \
params device="/dev/disk/by-id/scsi-vol01" directory="/srv/www"
op monitor interval=120s
What this has done is to start up dlm-clone and o2cb-clone on all three
nodes. Since server3 is actually attached to a different physical disk,
and is not shared with server1 and server2 (but the block device name is
the same) I suspect this is going to cause problems. I’m not an expert
on the syntax inside of crm, so how can I start all of this on just
server1 and server2? I really just need csync2 for server3 to keep
/etc/passwd, /etc/shadow, and /etc/group in sync.
I had a few ideas:
- Start csync2 but not openais on server3
- Change the name for the block device on server3
- (probably the best option) - figure out syntax for how to not start
dlm-clone, o2cb-clone, and fs-clone on server3.
Anyone have any advice on how best to proceed with this?