[DRBD-user] Node failure in a tripple primary setup

[Lars Ellenberg]

On Fri, Mar 02, 2018 at 10:27:31AM +0100, Sascha Reule wrote:
> Hello,
> 
> We’ve setup a three node cluster with DRBD 9.2.0 where all three nodes are primary and UpToDate.

There is no "tripple primary" DRBD.

Even only "two primaries" can only work "cleanly" in a two node setup,
even with DRBD 9.0.x.  We simply have not implemented that yet.

The only valid use case for dual-primary with more than two nodes
(all others secondary, obviously) is the "temporary dual primary",
where one is not actively used until the other is no longer actively
used, as is the case with live migrating VMs. Which would not have to be
that way, it could do with single primary even, by switching roles "at
the righ time"; but hypervisors do not implement it that way currently.

-- 
: Lars Ellenberg
: LINBIT | Keeping the Digital World Running
: DRBD -- Heartbeat -- Corosync -- Pacemaker

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