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AlexVeber
Contributor
Contributor
‎08-12-2010 07:51 AM

Packet filter is not being enabled on a server that looses network connectivity

Hi,

We currenltly have a vCenter heartbeat installation using 2 vms on the same LAN.

Yesterday we lost all the network connection (vmware channel and public) to the primary vm which was ACTIVE at the time, after a short period of time the secondary vm detected the failure and became ACTIVE.

a few minutes later the network connectivity to the primary server returned but because it was still designated as ACTIVE by heartbeat and the packet filter was not blocking the public interface we got an ip conflict and a split brain situation.

heartbeart recovred from the split brain by shutting itself down on both servers and packet filtering the public interfaces, basiclly we lost the vCenter. I had to manually reactivate one node as ACTIVE and restart the replication.

Is this avoidable or is it by some desing? can I teell heartbeat to packet fillter a node that lost network connectivity all together so when it returns there will be no ip conflitct?

Thanks for your help.

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2 Replies
Spanky123
Contributor
Contributor
‎01-24-2011 07:06 PM

I see the same thing.  It would seem plausible that the active server that got off the network should eventually shutdown if it could.  The documentation states that by design two active servers would shutdown vcenter heartbeat, but if they implemented some shared quorum mechanism, that would ensure that only one server was active at a time.

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NFJen
Contributor
Contributor
‎01-25-2011 01:05 PM

By design the packet filter does not change states until vCenter Server Heartbeat is started or unless manually changed. There are configurations you can put in place to avoid this scenario.  I have linked a few Knowledge Base articles below.


First there is the Network Monitoring in the event only the Public is lost and then in the event the channel is lost there is Split Brian Avoidance.


Network Monitoring KB: http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1008467&sl...


Split Brain Avoidance KB: http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1008137&sl...


Most applicable article 

Avoiding Split-Brain in a LAN

http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1008603&sl...

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