[DRBD-user] HostA and HostB never see each other - what am I doing wrong?

[Luis Motta Campos]

  Hi, DRBDers

  I'm facing a funny problem here: I'm not able to connect my drbd
syncer on HostA (primary) to HostB (secondary).

  I'm using CentOS 5.1:

Linux HostA 2.6.18-53.1.4.el5 #1 SMP Fri Nov 30 00:45:55 EST 2007 x86_64
 x86_64 x86_64 GNU/Linux

  And I'm using the DRBD packages from the "Extra" repository:

kmod-drbd-8.0.6-1.2.6.18_53.1.4.el5
drbd-8.0.6-1.el5.centos

  My packages are correctly installed, no errors, no warnings,
everything seems to be in place.

  I have 3 network cards connected to this machine. It doesn't really
matter, as all the three share the same network physical media (at the
moment, for simplicity). They are on separated network addresses and
netmasks, thought. All my networks can see the corresponding peers and
are working fine.

  As this is a test, I've setted up a fake disk using a file and a
losetup(8) call to configure a loopback device where I could connect
DRBD. This is working fine.

  I followed the steps in the walk-through at
http://www.drbd.org/drbd8-howto+M5efa56e6465.html (well, almost - there
are some caveats in there), and my /etc/drbd.conf is like this (for the
moment):

##### /etc/drbd.conf #####
global {
    usage-count no; # participate on pooling about drbd - no
}

common {
  protocol C;
}

resource "dbfs" {
  syncer {
    rate 125M;
  }
  on HostA { # yes, this is my virtual machine hostname
    device      /dev/drbd0;
    disk        /dev/loop0;
    address     172.16.168.2:7791;
    meta-disk   internal;
  }
  on HostB { # yes, this is my virtual machine hostname
    device      /dev/drbd0;
    disk        /dev/loop0;
    address     172.16.168.3:7791;
    meta-disk   internal;
  }
}
##### EOF #####

I'm trying to start the service using /etc/init.d/drbd start, but I get
as far as the waiting screen telling me that the service is waiting for
the other host to show up.

I try to execute the service (/etc/init.d/drbd start) on HostB, and it
does exactly the same thing in both sides.

My log files doesn't show relevant error messages. I can send them if
you think it could have something relevant.

I just ran out of ideas, and would like to hear from you: what am I
doing wrong?

Suggestions, pointers, tutorials, documentation and information requests
are all welcome.

Many thanks in advance for your help.
Cheers
-- 
Luis Motta Campos (a.k.a. Monsieur Champs) is a software engineer,
Perl fanatic evangelist, and amateur {cook, photographer}