[DRBD-user] Start resources after full drbd sync

Lars Ellenberg lars.ellenberg at linbit.com
Tue Jul 5 13:24:46 CEST 2011

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


On Tue, Jul 05, 2011 at 01:16:32PM +0200, Bart Coninckx wrote:
> On 07/05/11 12:38, Pawel Warowny wrote:
> >Hi
> >
> >Is there any way to configure cluster (pacemaker), so that some
> >resource start only after drbd full synchronisation?
> >
> >My configuration looks like this:
> >Two nodes with kvm virtualized guests.
> >
> >node1:
> >drbd ->  dlm ->  some other resources ->  libvirtd ->
> >->  VirtualDomain1, VirtualDomain2, (...)
> >
> >node2
> >drbd ->  dlm ->  some other resources ->  libvirtd ->
> >->  VirtualDomain5, VirtualDomain6, (...)
> >
> >VirtualDomains can move between nodes in case of some node is
> >unavailable.
> >
> >What Am I worry about:
> >
> >- some bad thing happened on node2
> >- node1 stonith node2, so node2 is rebooted
> >- VirtualDomains from node2 migrate to node1
> >- node2 started after reboot and starting cluster resources
> >- node2: drbd resync and getting primary before full sync.
> >- after drbd promotion all other resources is starting on node2
> >- VirtualDomains which migrated after stonith now is going back to node2
> >
> >and here is the problem, I don't want this migration while drbd is
> >syncing. It leads to heavily I/O load while drbd is syncing and at the
> >same time VirutalDomains are migrating. Under heavy I/O load migration
> >is slow and inefficient .
> >
> >Even worse, while drbd is syncing and VirtualDomains are migrating
> >under heavy load some VirtualDomain migration failed and because
> >of that node2 stonith node1.
> >
> >In this situation node1 is rebooting and we have inconsistent drbd
> >resource on node2 so every resource above drbd will fail.
> >Node1 started after reboot and again stonith node2 because failed
> >resources on it.
> >
> >I know that I can configure resource stickiness which will prevent
> >migration but this auto migration is important feature for me.
> >
> >Best regards
> 
> I don't think the resource will become primary before having fully synced.


Configure DRBD resource level fencing,
using e.g. the crm-fence-peer handler.


-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.
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