Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Thu, Dec 15, 2005 at 11:22:32AM +0100, Lars Ellenberg wrote: > / 2005-12-14 19:51:04 +0100 > \ Christof Amelunxen: > > Hi, > > > > Lars Marowsky-Bree wrote: > > > On 2005-12-14T18:59:29, Christof Amelunxen <ca at ordix.de> wrote: > > >> > > >> 1. NodeA (P) --- NodeB (S) # everything ok > > >> 2. NodeA (P) - - NodeB (S) # DRBD detects connection loss, goes WFC > > >> 3. NodeA (P) - - NodeB (S) # Linux-HA detects split brain, A kills B > > >> 4. / - - NodeB (P) # NodeB takes over, goes primary > > >> > > >> There have been writes on NodeA between step 2 and 3. These are lost > > >> after > > >> Linux-HA has killed A and made B primary. I know the best solution is to > > >> avoid this situation by any chance and we are using serial heartbeats, > > >> too, but what if it happens anyway? > > > > > > The writes are lost. > > > > Does that mean in this case automatical failover without any human > > intervention is not possible at all if data loss is unacceptable? > > In short, yes. > > In DRBD 8 we can avoid this. > NodeA will block writes right at 2., and trigger a callback. Clearly I've guessed badly at what drbd 0.7 does, sorry for the confusion. Could I get you to elaborate on what Protocols A,B and C do in drbd-0.7 and in relation to connection loss ? Regards, Paddy -- Perl 6 will give you the big knob. -- Larry Wall