Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
I've got a pair of systems with a pair of volumes that, due to a previously discussed problem with large partition sizes, is running only one pair using drbd. i.e.: System 1 System 2 sda1 -------RSYNC------ sda1 sdb1 -------DRBD0----- sdb1 The sda1's are kept in sync with periodic rsync's, as shown above. Now that we have the problem resolved, I'd like to change it so sdb1 is using DRBD as well. But the trick is, System 2's sdb1 is not necessarily up to date/in sync with System 1's -- It is VERY IMPORTANT that as a part of this change that System 1's sdb1 is the PRIMARY copy of the data. (For reasons not worth going into here, it's non-feasible to sync this data before the copy) My plan right now is to move these disks that comprise these volumes to another pair of systems, one that's been built all spankin' new and clean that has drbd properly integrated with heartbeat. The only thing I need to make absolutely sure of is that everything comes up in an order where I can clearly control which system is the primary/master heartbeat node. My plan right now is: Make sure drbd/heartbeat does NOT start on boot Bring up both systems, verify drbd is not running/synced. Load drbd modules on each system. On System 2 (STALE copy): drbdsetup /dev/nb0 disk /dev/sda1 drbdsetup /dev/nb1 disk /dev/sdb1 drbdsetup /dev/nb0 net 172.16.1.101:7788 172.16.1.100:7788 B drbdsetup /dev/nb1 net 172.16.1.101:7789 172.16.1.101:7789 B On System 1 (GOOD copy): drbdsetup /dev/nb0 disk /dev/sda1 drbdsetup /dev/nb1 disk /dev/sdb1 drbdsetup /dev/nb0 primary drbdsetup /dev/nb1 primary drbdsetup /dev/nb0 net 172.16.1.100:7788 172.16.1.101:7788 B drbdsetup /dev/nb1 net 172.16.1.100:7789 172.16.1.101:7789 B At this point, I'll verify the partitions are syncing as expected, and System 1 is the primary. (If it's not I'm screwed.) Note that in this example, whereas the sdb1 pair was nb0, now it'll be nb1. If everything's going ok, then on System 1 I'll crank up heartbeat with '/etc/init.d/heartbeat start'. datadisk may complain a little about seeing the volumes already started, but within a minute I should see System 1 become the master heartbeat node, at which time I can safely crank up System 2's heartbeat. Does all this make sense? Is there anything else I need to/can do to make absolutely sure that System 1's copy of the data will be the 'real' one? Brian