Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
JR wrote: >Yea I was out of pocket for a few days, but basically, you end up with 3 DRBD devices, 1 per VM/service right? Yes. And every DRBD device on his own LV. Same thing on the second node. >When I said "dual-primary" I was speaking of DRBD only. DRBD in "dual-primary" >aka "active-active" is analogous to a "shared storage"--such as a DAS or SAN connected to servers via HBAs with the same LUN mapped to both servers--modulo split-brain considerations as >explained above. That does *not* mean, that both identical vm's are running simultaneously on the two nodes, right ? >The reason you make it active-active on both nodes is because with Live-Migration the VM does exist simultaneously on both nodes for a brief period of time as the memory pages/state are >migrated over and both access the block device simultaneously yet in a synchronized manner through the underlying HyperVisor. Indeed, there is a mechanism in place for synchronization as your >surmised there must be. Don't I need a cluster aware FS for that short period of time when both are running ? What mechanism for synchronization do you mean ? Can I realise the Live migration with cluster tools, or with KVM tools ? If I use KVM tools, don't they interfere with the HA-Software ? Bernd