CAS reboot causes DAG failover (Full Version)

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HitBear -> CAS reboot causes DAG failover (7.Apr.2011 6:12:51 AM)

Hi, I'm new here. So:

Anyway, I have an interesting one for you.
We rebooted one of our CAS servers, and a couple of seconds later the DAG failed over.
Is this normal and has anyone seen it or something like it before?


HitBear -> RE: CAS reboot causes DAG failover (7.Apr.2011 7:18:57 AM)

Sorry, maybe a little more information is needed here..

There are two sites. A+B
Both have CAS/HUB roles co-located on one server front ending a single node in the DAG.

A reboot of this server (the CAS\HUB) server appears to cause the mailboxes to activate on the second node in the DR site. I think this might be down to the DR CAS\HUB being on site B and the only remaining CAS\HUB in the organization.

Am I thinking correctly or can there be another reason for the failover behaviour?


de.blackman -> RE: CAS reboot causes DAG failover (7.Apr.2011 8:23:27 AM)

On which machine do you have your file share witness?

HitBear -> RE: CAS reboot causes DAG failover (7.Apr.2011 10:43:12 AM)

Neither AFIK. It was a reboot of the machine hosting the CAS and HUB roles only the witness share wasn't effected, but don't quote me on that...

BTW thanks for the reply.

de.blackman -> RE: CAS reboot causes DAG failover (7.Apr.2011 10:57:42 AM)

Can you find out which machine is the file share witness is on? Microsoft recommends it to be on a hub transport server so I am thinking it is the rebooted server. Also is your second site an active (the mailbox server contains active databases) or strictly passive (contains only passive copies of the databases)? Also please run Get-DatabaseAvailabilityGroup | FL and post the results.

HitBear -> RE: CAS reboot causes DAG failover (13.Apr.2011 3:54:57 AM)

Sorry this is in the wrong forum.
It's exchange 2007, on a 2003 cluster. The FSW is on the Hub/Client server that was rebooted.

Sorry for the confusion, it's been a heck of a week here...

RustyShackleford -> RE: CAS reboot causes DAG failover (14.Apr.2011 8:42:27 PM)

What did you find out?

HitBear -> RE: CAS reboot causes DAG failover (9.May2011 3:58:46 AM)

Sorry for the delay,

It appears that the FSW is on the CAS/HUB. Furthermore the archetect used round robin DNS to load balance between the two CAS/HUBs in either site. It took me some time to schedule the test, but over the weekend I downed the CAS/HUB and it caused a failure in the cluster service on the primary node.

Had to fail it back.

Whetehr it's normal or not, that is whats happening.

BTW thanks for your patience in this.

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