[DRBD-user] What indication of outstanding writes when WFConnection?

[Leroy van Logchem]

Mark Yarborough wrote:

>Hello all,
>
>Can someone clarify the warnings you might get when running protocol C and a 
>write to the primary cannot be replicated to the secondary?  Like so:
>
>1. Primary and Secondary both cs:Connected
>2. Disconnect DRBD line (only)
>3. Primary and Secondary both cs:WFConnection
>4. Write to DRDB partition on primary
>5. ???????
>6. Reconnect DRBD line
>7. Primary and Secondary both cs:Connected
>
>At step 5 the primary and secondary partitions 
>were out of sync, because the DRBD line was down.
>>From the primary, at step 5, is there any way to tell
>that the partitions are out of sync? Any message logged?
>  
>
IMO: The drbd state machine always marks the device out-of-sync if 
disconnected from the primary ( even if it's only for a short while ). 
Your primary mounted filesystem will always change a bit if it where 
only the timestamps. From WFConnection to Connected the state is 
exchanged and typically the next state is resync. So just monitoring for 
anything other then "Connected" when issued a "drbdadm cstate all" 
should be enough to report a event using Nagios/NetSaint.

--Leroy