+
+=== DRBD optimization ===
+
+The default DRBD parameters are not really optimized, which means very slow (re)syncing. The
+following commands might help to make it faster. Of course the max speed can be increased if
+both the network and disk speed allow that.
+
+{{{
+ gnt-cluster modify -D drbd:net-custom="--max-buffers 36k --sndbuf-size 1024k --rcvbuf-size 2048k"
+ gnt-cluster modify -D drbd:c-min-rate=32768
+ gnt-cluster modify -D drbd:c-max-rate=98304
+ gnt-cluster modify -D drbd:resync-rate=98304
+}}}
+
+
+=== Change the disk cache ===
+
+When using raw volumes or partitions, it is best to avoid the host cache completely to reduce data copies
+and bus traffic. This can be done using:
+
+{{{
+ gnt-cluster modify -H kvm:disk_cache=none
+}}}
+
+