[ClusterLabs] Question on sharing data with DRDB

[Digimer]

On 2019-03-20 2:00 p.m., Valentin Vidic wrote:
> On Wed, Mar 20, 2019 at 01:47:56PM -0400, Digimer wrote:
>> Not when DRBD is configured correctly. You sent 'fencing
>> resource-and-stonith;' and set the appropriate fence handler. This tells
>> DRBD to not proceed with a write while a node is in an unknown state
>> (which happens when the node stops responding and is cleared on
>> successful fence).
> 
> The situation I had in mind is this: node1 is Primary and sends a write to
> local disk and over the DRBD link. The network fails so the write is
> successfull only on the local disk. node1 is than fenced and node2 takes
> over but the disk have now diverged.

This is handled by using Protocol C in DRBD. That tells DRBD to not
consider a write complete until it has hit persistent storage on both nodes.

-- 
Digimer
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