Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
If I want to run VMs on both node 1 & node 2 they would need to be setup as dual primaries, is this not the case? What I was trying to achive was two on-site servers that could fail over to one another OR in case both die node 3 runs all the servers (rather slowly of course!) Sorry for my ignorance but I dont quite understand your diagram for the alternative. Lars Ellenberg wrote: > > On Thu, Sep 08, 2011 at 04:52:28PM +0200, Florian Haas wrote: >> On 09/08/11 15:06, SlingPirate wrote: >> > >> > I have 3 servers two are to run in dual primary mode (node 1 and 2) >> while a >> > third (node 3) is to be an off-site backup. I have got the first 2 >> nodes >> > sync'd and in primary mode quite happily but I can't get the backup >> node to >> > sync. Every time I try to bring the stacked resource into primary on >> node 1 >> > (even with node 2 in secondary) it complains that it "needs access to >> > UpToDate data". >> > >> > Am I just doing things wrong by trying to do a dual primary with a >> stacked >> > backup? >> >> Yes. This can't work. > > Well. You can do this: > > [ upper Primary node 1 ] ---- [ upper Primary node 2 ] > [ lower DRBD node 1 ] > `------.[ DR node ] > > And live with the fact that, if you lose node 1, you lose your DR link. > If you want to resume the DR replication from node 2, > you need a full sync to the DR site. > > [If you do a planed migration of the DR link to node 2 (no crash > involved), you can do so without a full sync to the DR site, but you'd > need to know more DRBD internals than are good for me :-)] > > If you lose node 1 catastrophically, and you now need to resume the DR > replication from node 2, you will still need a full sync to the DR site. > > > > This can not work: > [ upper Primary node 1 ]------------------------------------------ [DR ] > [ lower Primary node 1 ]-----[ lower Primary node 2 ] > > Because there is no way for writes from node2 to reach DR in this > picture, [DR] would receive only half of the writes, thus have a > corrupted dataset by design. > > > Maybe you don't need dual primary anyways? > Very few installations actually do. > > -- > : Lars Ellenberg > : LINBIT | Your Way to High Availability > : DRBD/HA support and consulting http://www.linbit.com > > DRBD® and LINBIT® are registered trademarks of LINBIT, Austria. > __ > please don't Cc me, but send to list -- I'm subscribed > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user > > -- View this message in context: http://old.nabble.com/Enabling-a-stacked-resource---HELP%21-tp32423513p32424927.html Sent from the DRBD - User mailing list archive at Nabble.com.