[DRBD-user] Forcibly disconnect if secondary is responding too slow?

Felix Zachlod fz.lists at sis-gmbh.info
Fri Nov 7 10:20:05 CET 2014

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

Am 07.11.2014 09:46, schrieb Lars Ellenberg:
> Right there.
> DRBD config setting is ko-count.
> Also, please use drbd 8.4 (where that would default to 7, iirc).

Hello Lars,

thanks for your answer. The ko-count seems promising but how to deal 
with such a problem on the primary? That would stilly need to detach to 
go on in diskless mode, am I right about this?

I can seen that generally the behaviour of the raid card is wrong and 
should be investigated but I can imagine other situations where DRDB has 
to handle a problem like this e.g. a raid card getting totally 
unresponsive for some reason. I assume this has to be dealt with 
disk-timeout, right?

And yes I know we should upgrade to 8.4. and we are in point of doing 
this but I still have to do some testing before touching this setup and 
it would be nice if I could get all those config right with the upgrade.

> See above: ko-count.
> also, you could have used --force disconnect (if no other drbdsetup is
> blocking yet), or instead resetting the other box, simply cut the tcp
> connection (iptables or any other tool you may be more comfortable with).

I just realized that I could have done something like that later but you 
know in these situations where you just search for a solution to get out 
asap you don't always use the best one...

Finally it didn't hurt to reset the peer but I would like to have a 
configuration in place that deals with such problems itself as far as 
possible without interaction, it was just by accident that I noticed 
this problem immediately and in another situation the I/O might have 
been hanging around for a lot longer time before someone finds the root 
cause ... probably causing ALL VMs residing on this setup to remount 
their filesystems r/o ... and that are just the moments I hate ;)

regards, Felix

More information about the drbd-user mailing list