[Drbd-dev] DRBD-8: weirdness with netlink/connector

[Philipp Reisner]

Am Freitag, 13. Oktober 2006 21:02 schrieb Graham, Simon:
> We have noticed that when issuing a sequence of drbdadm secondary &
> primary commands, we get errors from the underlying drbdsetup command
> like this:
>
> [root at adam ~]# drbdadm secondary vm1.root.fs
> [root at adam ~]# drbdadm primary vm1.root.fs
> [root at adam ~]# drbdadm secondary vm1.root.fs
> No response from the DRBD driver! Is the module loaded?
>
> I noticed in the code that this error message is produced in a loop that
> keeps reading from the netlink socket until it gets the expected reply
> and also that there was some commented out trace code that would print
> info if an unexpected reply was seen so I enabled this and now see
> things like this:
>
> [root at adam ~]# drbdadm secondary vm1.root.fs
> [root at adam ~]# drbdadm primary vm1.root.fs
> INFO: got other message
> got seq: 110 ; ack 0
> exp seq: 1 ; ack 1849768433
> [root at adam ~]# drbdadm secondary vm1.root.fs
> INFO: got other message
> got seq: 111 ; ack 0
> exp seq: 1 ; ack 299691195
> No response from the DRBD driver! Is the module loaded?
>
> This is very reproducible and is presumably either due to the wrong size
> messages being sent by the kernel or some sort of data corruption in
> drbdsetup - I figured you guys might have a better handle on fixing this
> quickly!

Hi Simon,

I also noticed this already. It is simply a too small timeout in drbdsetup.
I just changed it from 300ms to 5 seconds. 

BTW, the "other messages" are the status events broad casted by DRBD 
on every state change. It is ok, that drbdsetup gets those messages.

-Phil
-- 
: Dipl-Ing Philipp Reisner                      Tel +43-1-8178292-50 :
: LINBIT Information Technologies GmbH          Fax +43-1-8178292-82 :
: Schönbrunnerstr 244, 1120 Vienna, Austria    http://www.linbit.com :