Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi Cyril, > I would like DRBD to start as fast as possible at boot time on every > nodes (without any timeout or user input) and let Heartbeat or the > sysadmin decide whenever one node or the other should become primary > or secondary. I don't want DRBD to make cluster-wide decisions > because it's (just) a block device driver. There's more to drbd than being a block device - drbd is the only one in the cluster with reliable information on which node in the cluster has valid and/or up to date information. * Heartbeat can not determine which node last had the device and which side has the most recend data. * Drbd can not determine which side has the most recent data without connecting to the oder side and comparing metadata. So, the only reliable way to start a cluster is to let drbd connect to the other side and make a source/target decision for sync/replication based on the local and remote metadata. As of version 0.7 this is independent from primary/secondary state, which can (and should be) set by heartbeat. This argument gets should make you want to give drbd a chance to connect to the secondary. Decision time: is data integrity or availability more important to you? * if integrity is most important: you must wait until drbd can reach the secondary or until an operator manually intervenes before continuing startup. this is the default configuration. * if availability is most important, and you knowingly accept the possibility that you my lose data: set a timeout for drbd connect and allow it to continue startup if the 2nd node can't be reached. Timeout should be long anough to allow a connection to be established under reasonable circumstances; in configurations where I use this type of setup, timeout is usually set to 15-20 minutes, with a shorter timeout for degraded wfc (i.e the other node wasn't there before shutdown). This timeout only gets to expire if * both nodes of a cluster are down at the same time * one of them doesn't come up after startup * they were BOTH available and connected before shutdown. > At this time and according to the manual, I haven't found a way to > make such a configuration properly. > > Is there a way to tell DRBD not to become primary at boot time and at > the same time not to wait for a secondary? I don't think you want to do that, see above. Bye, Martin