DRBD

apt-get install drbd8-utils

global {
  usage-count no;
}

common {
  startup {
    wfc-timeout  30;
    degr-wfc-timeout 15;
    outdated-wfc-timeout 10;
  }

  net {
    protocol C;
    shared-secret "MyS3cre3t";
    max-buffers 36k;
    sndbuf-size 1024k;
    rcvbuf-size 2048k;
  }

  syncer {
    rate 4194304k;
    al-extents 6433;
  }

  disk {
    on-io-error detach;
    c-plan-ahead 2;
    c-fill-target 24M;
    c-min-rate 80M;
    c-max-rate 720M;
  }
}

resource r0 {
  device /dev/drbd0;
  disk /dev/sdb;
  meta-disk internal;

  on drbd1.eisscholle.net {
    address 10.0.0.101:7788;
  }

  on drbd1.eisscholle.net {
    address 10.0.0.102:7788;
  }
}

root@drbd1:~# drbdadm create-md r0; /etc/init.d/drbd start
root@drbd2:~# drbdadm create-md r0; /etc/init.d/drbd start

root@drbd1:~# drbdadm -- --overwrite-data-of-peer primary r0
root@drbd1:~# mkfs.ext4 /dev/drbd0