832
858
DRBD usually uses the TCP socket option TCP_CORK to hint to the network stack when it can expect more data, and when it should flush out what it has in its send queue\&. It turned out that there is at least one network stack that performs worse when one uses this hinting method\&. Therefore we introducted this option, which disables the setting and clearing of the TCP_CORK socket option by DRBD\&.
861
\fBon\-congestion \fR\fB\fIcongestion_policy\fR\fR, \fBcongestion\-fill \fR\fB\fIfill_threshold\fR\fR, \fBcongestion\-extents \fR\fB\fIactive_extents_threshold\fR\fR
865
When DRBD is deployed with DRBD\-proxy it might be more desirable that DRBD goes into AHEAD/BEHIND mode shortly before the send queue becomes full\&. In AHEAD/BEHIND mode DRBD does no longer replicate data, but still keeps the connection open\&.
867
The advantage of the AHEAD/BEHIND mode is that the application is not slowed down, even if DRBD\-proxy\*(Aqs buffer is not sufficient to buffer all write requests\&. The downside is that the peer node falls behind, and that a resync will be necessary to bring it back into sync\&. During that resync the peer node will have an inconsistent disk\&.
835
884
\fBwfc\-timeout \fR\fB\fItime\fR\fR
837
886
Wait for connection timeout\&.