resource r0 {

  # transfer protocol to use.
  # C: write IO is reported as completed, if we know it has
  #    reached _both_ local and remote DISK.
  #    * for critical transactional data.
  # B: write IO is reported as completed, if it has reached
  #    local DISK and remote buffer cache.
  #    * for most cases.
  # A: write IO is reported as completed, if it has reached
  #    local DISK and local tcp send buffer. (see also sndbuf-size)
  #    * for high latency networks
  #
  #**********
  # uhm, benchmarks have shown that C is actually better than B.
  # this note shall disappear, when we are convinced that B is
  # the right choice "for most cases".
  # Until then, always use C unless you have a reason not to.
  #	--lge
  #**********
  #
  protocol C;

  # what should be done in case the cluster starts up in
  # degraded mode, but knows it has inconsistent data.
  incon-degr-cmd "echo '!DRBD! pri on incon-degr' | wall ; sleep 60 ; halt -f";

  startup {
    # Wait for connection timeout. 
    # The init script blocks the boot process until the resources
    # are connected. This is so when the cluster manager starts later,
    # it does not see a resource with internal split-brain.
    # In case you want to limit the wait time, do it here.
    # Default is 0, which means unlimited. Unit is seconds.
    #
    #   wfc-timeout  180;

    # Wait for connection timeout if this node was a degraded cluster.
    # In case a degraded cluster (= cluster with only one node left)
    # is rebooted, this timeout value is used. 
    #
    degr-wfc-timeout 5;    # 5 seconds.
  }

  disk {
    # if the lower level device reports io-error you have the choice of
    #  "pass_on"  ->  Report the io-error to the upper layers.
    #                 Primary   -> report it to the mounted file system.
    #                 Secondary -> ignore it.
    #  "panic"    ->  The node leaves the cluster by doing a kernel panic.
    #  "detach"   ->  The node drops its backing storage device, and
    #                 continues in disk less mode.
    #
    on-io-error  pass_on;

    # In case you only want to use a fraction of the available space
    # you might use the "size" option here.
    #
    # size 10G;
  }

  net {
    # this is the size of the tcp socket send buffer
    # increase it _carefully_ if you want to use protocol A over a
    # high latency network with reasonable write throughput.
    # defaults to 2*65535; you might try even 1M, but if your kernel or
    # network driver chokes on that, you have been warned.
    # sndbuf-size 512k;

     timeout       50;    #  6 seconds  (unit = 0.1 seconds)
     connect-int   10;    # 10 seconds  (unit = 1 second)
     ping-int      10;    # 10 seconds  (unit = 1 second)

    # Maximal number of requests (4K) to be allocated by DRBD.
    # The minimum is hardcoded to 32 (=128 kByte).
    # For high performance installations it might help if you
    # increase that number. These buffers are used to hold
    # datablocks while they are written to disk.
    #
    # max-buffers     2048;

    # The highest number of data blocks between two write barriers. 
    # If you set this < 10 you might decrease your performance.
    # max-epoch-size  2048;

    # if some block send times out this many times, the peer is 
    # considered dead, even if it still answers ping requests.
    # ko-count 4;

    # if the connection to the peer is lost you have the choice of
    #  "reconnect"   -> Try to reconnect (AKA WFConnection state)
    #  "stand_alone" -> Do not reconnect (AKA StandAlone state)
    #  "freeze_io"   -> Try to reconnect but freeze all IO until
    #                   the connection is established again.
    on-disconnect reconnect;

  }

  syncer {
    # Limit the bandwith used by the resynchronisation process.
    # default unit is kByte/sec; optional suffixes K,M,G are allowed.
    #
    # Even though this is a network setting, the units are based
    # on _byte_ (octet for our french friends) not bit.
    # We are storage guys.
    #
    # Note that on 100Mbit ethernet, you cannot expect more than
    # 12.5 MByte total transfer rate.
    # Consider using GigaBit Ethernet.
    #
    rate 10M;

    # All devices in one group are resynchronized parallel. 
    # Resychronisation of groups is serialized in ascending order. 
    # Put DRBD resources which are on different physical disks in one group.
    # Put DRBD resources on one physical disk in different groups.
    #
    group 1;

    # Configures the size of the active set. Each extent is 4M, 
    # 257 Extents ~> 1GB active set size. In case your syncer
    # runs @ 10MB/sec, all resync after a primary's crash will last
    # 1GB / ( 10MB/sec ) ~ 102 seconds ~ One Minute and 42 Seconds.
    # BTW, the hash algorithm works best if the number of al-extents
    # is prime. (To test the worst case performace use a power of 2)
    al-extents 257;
  }

  on clust0 {
    device     /dev/drbd0;
    disk       /dev/i2o/hda4;
    address    10.0.0.10:7788;
    meta-disk  internal;

    # meta-disk is either 'internal' or '/dev/ice/name [idx]'
    #
    # You can use a single block device to store meta-data
    # of multiple DRBD's.
    # E.g. use meta-disk /dev/hde6[0]; and meta-disk /dev/hde6[1];
    # for two different resources. In this case the meta-disk
    # would need to be at least 256 MB in size.
    #
    # 'internal' means, that the last 128 MB of the lower device
    # are used to store the meta-data.
    # You must not give an index with 'internal'.
  }

  on clust1 {
    device    /dev/drbd0;
    disk      /dev/i2o/hda4;
    address   10.0.0.15:7788;
    meta-disk internal;
  }
}