[DRBD-user] Just restarting secondary causes split brain,can someone expain why please?

Francesco Ciocchetti francesco.ciocchetti at kyneste.com
Tue Mar 6 11:01:11 CET 2007

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


I' ve a newbie about DRBD but i experienced a problem like your one. In
my case the problem was the setting of the following configuration
instructions:

I had to change the first one to this value to be able to regain from
the SB.


after-sb-0pri discard-younger-primary;
after-sb-1pri consensus;
after-sb-2pri disconnect;


Bye

David wrote:
>
> Before reboot:
>
> hydrogen:/etc/ha.d # cat /proc/drbd
> version: 8.0.1 (api:86/proto:86)
> SVN Revision: 2784 build by root at hydrogen, 2007-03-05 08:47:01
> 0: cs:Connected st:Primary/Secondary ds:UpToDate/UpToDate C r---
> ns:264 nr:0 dw:256 dr:580 al:0 bm:2 lo:0 pe:0 ua:0 ap:0
> resync: used:0/31 hits:20 misses:2 starving:0 dirty:0 changed:2
> act_log: used:0/127 hits:25 misses:0 starving:0 dirty:0 changed:0
>
> oxygen:~ # cat /proc/drbd
> version: 8.0.1 (api:86/proto:86)
> SVN Revision: 2784 build by root at oxygen, 2007-03-05 08:43:02
> 0: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
> ns:0 nr:264 dw:264 dr:0 al:0 bm:2 lo:0 pe:0 ua:0 ap:0
> resync: used:0/31 hits:20 misses:2 starving:0 dirty:0 changed:2
> act_log: used:0/127 hits:0 misses:0 starving:0 dirty:0 changed:0
>
>
> During hydrogen reboot:
> oxygen:~ # cat /proc/drbd
> version: 8.0.1 (api:86/proto:86)
> SVN Revision: 2784 build by root at oxygen, 2007-03-05 08:43:02
> 0: cs:WFConnection st:Primary/Unknown ds:UpToDate/DUnknown C r---
> ns:0 nr:264 dw:520 dr:316 al:0 bm:2 lo:0 pe:0 ua:0 ap:0
> resync: used:0/31 hits:20 misses:2 starving:0 dirty:0 changed:2
> act_log: used:0/127 hits:25 misses:0 starving:0 dirty:0 changed:0
>
>
> Started drbd (no heartbeat) on hydrogen
> oxygen:~ # cat /proc/drbd
> version: 8.0.1 (api:86/proto:86)
> SVN Revision: 2784 build by root at oxygen, 2007-03-05 08:43:02
> 0: cs:StandAlone st:Primary/Unknown ds:UpToDate/DUnknown r---
> ns:0 nr:264 dw:520 dr:316 al:0 bm:2 lo:0 pe:0 ua:0 ap:0
> resync: used:0/31 hits:20 misses:2 starving:0 dirty:0 changed:2
> act_log: used:0/127 hits:25 misses:0 starving:0 dirty:0 changed:0
>
> On hydrogen, I'm seeing:
> hydrogen:~ # service drbd start
> Starting DRBD resources: [ d0 s0 n0 ].
> ..........
> ***************************************************************
> DRBD's startup script waits for the peer node(s) to appear.
> - In case this node was already a degraded cluster before the
> reboot the timeout is 0 seconds. [degr-wfc-timeout]
> - If the peer was available before the reboot the timeout will
> expire after 0 seconds. [wfc-timeout]
> (These values are for resource 'r0'; 0 sec -> wait forever)
> To abort waiting enter 'yes' [ 520]:
>
>
>
> So just starting drbd on hydrogen causes a split brain and oxygen, now
> the primary, to go into a standalone state. Why is that? The file
> system is mounted as a read only file system so no changes should be
> taking place. This is not a primary/primary setup so there is only one
> "active" node at a time. I was under the impression that the rebooting
> node, hydrogen, should see that it is out of date and become
> secondary, resync itself with the primary and stay in the secondary
> state until that is changed? Am I wrong?
>
> Both systems are identical:
> SLES 10
> kernel 2.6.16.27-0.9-bigsmp
> drbd 8.0.1 compiled from source
>
>
> Thanks ahead,
>
> David
>
>
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user
>

-- 
==============================================
Francesco Ciocchetti (francesco.ciocchetti at kyneste.com)

Network & Security
Kyneste - Piattaforme ICT
"Società appartenente al Gruppo Bancario Capitalia e
sottoposta all’attività di direzione e coordinamento di Capitalia S.p.A."
Via Mario Bianchini 68, 00142 Roma
T.[+39] 06.98402.1 F. [+39] 06.98402.300
http://www.kyneste.com/
==============================================

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