Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Fri, Feb 24, 2017 at 03:08:04PM +0100, Dr. Volker Jaenisch wrote: > Hi DRBD_users! > > We have a drbd 8.4 setup with two nodes over distance lines, with one > not so common feature, we like to discuss here. > > Host A ========== 2 x 10GBit lines ======== Host B > > | --------------- DSL 2Mb/s Line ------------| > > The nodes are connected via two redundant 10Gbit links which are port > channeled/bonded in an interface bond0 on the nodes. Lets call this bond > the "worker" connection. > > Pacemaker (corosync) features two rings: One over bond0 (the worker > connection) and the second over an additional link (DSL peer-2-peer > 2Mbit/sec). Lets call this DSL-Link the "heartbeat" connection. This > additional hearbeat line is the non standard part. > > The configurations of corosync, pacemaker, drbd are from the textbook > and in no way spezial. > > > Testing disaster szenarios we discovered the following corner case: > > If both 10Gbit links fail then the bond0 aka the worker connection fails > and DRBD goes - as expected - into split brain. But that is not the problem. DRBD will be *disconnected*, yes. But no reason for it to be "split brain"ed yet. and with proper fencing configured, it won't. > The problem is that pacemaker obviously does not notice the split brain. Huh? No split brain yet. So why would it notice. > So pacemaker cannot solve this condition by itself. But Yes it can. Or you did not provide enough context. -- : Lars Ellenberg : LINBIT | Keeping the Digital World Running : DRBD -- Heartbeat -- Corosync -- Pacemaker DRBD® and LINBIT® are registered trademarks of LINBIT __ please don't Cc me, but send to list -- I'm subscribed