HA and DRBD in Linux

# cat drbd.conf

# please have a a look at the example configuration file in
# /usr/share/doc/drbd/drbd.conf
#
resource r0 {
        protocol C;
        startup {
    degr-wfc-timeout 120;    # 2 minutes.
  }
        disk {
    on-io-error   detach;
  }
        net {
  }
syncer {
        rate 20M;
  }
  on IDCeLearning01 {
    device    /dev/drbd0;
    disk      /dev/cciss/c0d0p3;
    address   192.168.100.10:7789;
    meta-disk internal;
  }
  on IDCeLearning02 {
    device    /dev/drbd0;
    disk      /dev/cciss/c0d0p3;
    address   192.168.100.20:7789;
    meta-disk internal;
  }
}


# cat /etc/ha.d/ha.cf
debugfile       /var/log/ha-debug
logfile         /var/log/ha-log
logfacility     local0
keepalive       2

deadtime        30
warntime        10
initdead        120
udpport         694

ucast           eth1 10.82.130.91
auto_failback   off
node            IDCeLearning01 IDCeLearning02


# cat /etc/ha.d/haresources
IDCeLearning01 192.168.100.15/32/192.168.100.15 drbddisk::r0 Filesystem::/dev/drbd0::/mnt/shared::ext3 nfs

DRBD Links
http://linux-ha.org/
http://www.howtoforge.com/drbd-on-centos-4.5
http://wiki.centos.org/HowTos/Ha-Drbd
http://www.linuxjournal.com/article/9074
http://www.nabble.com/Kernel-Panic-using-LVM2-over-DRBD-8.0.6-td14124742.html