I've noticed with testing my SQL Server cluster failover,
that SQL Server is unavailable during the fail over.

I noticed that when the SQL Server serice is starting on
the fail over node, No one can connect until the service
is started on the backup node.

Is there any way to aviod this when the failover is
occuring.

This behavior is expected( by design)......any cluster resource( including
SQL) will not be available during a fail-over.
Thanks,
--
Sandeep Sutari
Microsoft Corp.

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"John Oberkehr" <jobie61 (AT) yahoo (DOT) com> wrote

And to add to that, you have the SQL Server service shutting down during a
failover. The disk ownership is transferred and then the SQL Server service
is started back up. When SQL Server starts up, it goes through restart
recovery. That means while the cluster comes up and the SQL Server service
starts, your database will not be accessible until the undo portion of
restart recovery completes. This is affected by the run duration of any
transaction which was in flight when the cluster failed over.

As an example, if you had a transaction that had been running for 20 hours
when the cluster fails over, the database(s) that is was operating on will
not come back online until approximately 20 hours after fail over.

--

Mike
Principal Mentor
Solid Quality Learning
"More than just Training"
SQL Server MVP
http://www.solidqualitylearning.com
http://www.mssqlserver.com