[Samba] ocfs2 problem on ctdb cluster

[steve]

Ubuntu 14.04, drbd
Hi
On a drbd Primary node, when attempting to mount our cluster partition:
sudo mount -t ocfs2 /dev/drbd1 /cluster
we get:
mount.ocfs2: Unable to access cluster service while trying to join the
group

We then call:
sudo dpkg-reconfigure ocfs2-tools
Setting cluster stack "o2cb": OK
Starting O2CB cluster ocfs2: OK

And all is well:
Aug 22 13:48:23 uc1 kernel: [ 1181.117051] o2dlm: Joining domain
B044256AC5F14DB089B4C87F28EE9583 ( 1 ) 1 nodes
Aug 22 13:48:23 uc1 kernel: [ 1181.258192] ocfs2: Mounting device
(147,1) on (node 1, slot 0) with ordered data mode.

 mount | grep cluster
/dev/drbd1 on /cluster type ocfs2 (rw,_netdev,heartbeat=local)


Why doesn't o2cb 'stick' after a reboot?
Thanks,
Steve

 /etc/ocfs2/cluster.conf 
node:
        ip_port = 7777
        ip_address = 192.168.0.10 
        number = 1
        name = uc1
        cluster = ocfs2
node:
        ip_port = 7777
        ip_address = 192.168.0.11 
        number = 2
        name = uc2
        cluster = ocfs2
cluster:
        node_count = 2
        name = ocfs2

/etc/drbd.conf
global {
  usage-count yes;
}
common {
  net {
    protocol C;
  }
}

resource r0 {
 handlers {
   split-brain "/usr/lib/drbd/notify-split-brain.sh steve";
     }

net { 
  allow-two-primaries; 
  after-sb-0pri discard-zero-changes;
  after-sb-1pri discard-secondary;
  after-sb-2pri disconnect;
      }
 startup { 
  become-primary-on both;
          }
  on uc1 {
    device    /dev/drbd1;
    disk      /dev/sdb1;
    address   192.168.0.10:7789;
    meta-disk internal;
  }
  on uc2 {
    device    /dev/drbd1;
    disk      /dev/sdb1;
    address   192.168.0.11:7789;
    meta-disk internal;
  }
}

[global]
workgroup = ALTEA
realm = ALTEA.SITE
security = ADS
kerberos method = secrets only
netbios name = SMBCLUSTER
disable netbios = Yes
clustering = Yes
ctdbd socket = /var/lib/run/ctdb/ctdbd.socket
[users]
path = /cluster/users
read only = No
[profiles]
path = /cluster/profiles
read only = No
[shared]
path = /cluster/shared
force create mode = 0770
read only = No