Posts tagged Clustering
Had a strange error on a SQL 2008 cluster the other day,
The OS was Windows 2008 R2
We kept getting messages that the cluster node was offline because the Quorum was unavailable. This made little sense as both nodes in this cluster were online and the Quorum disk was available. We could ping across the heartbeat, everything looked fine except for these errors.
After a little research we determined that a new version of Symantec Endpoint Security had been pushed to these servers. Even with the new version of endpoint security, we could establish communication across all networks between the 2 nodes so we were a little stumped. Eventually we ran across a policy that was being enforced from the Symantec central management server/policy/whatever its called!
As it turns out, Symantec endpoint security by default blocks all IPV6 traffic. If you’re like me, I didn’t even realize that a windows 2008 cluster would use IPV6 for the heartbeat communication. After disabling the rules that were preventing IPV6 traffic everything returned to normal.
So, the moral of all this is nothing new… NEVER trust anything new getting pushed to your servers..
When its any version of SQL running on a clustered Windows 2003 Server or sql 2005 running on clustered Windows 2008 Server. Seems that while you can dynamically add a disk and use it in SQL when your running a standalone server, if your running in a “highly availiable” cluster configuration you have to take SQL offline to add the disk as a dependency in order to be able to use it within SQL. Here’s the proof right from SQL books online.
Im sure there was a good reason to require this at the time but clearly this wasnt thought out in the grand scheme of taking 0 downtime. Anytime a single server has a more highly availiable architecture than your system that is designed for high availibility –>youre doing it wrong, Sorry someone had to say it