Wednesday, March 28, 2012

Migrating Clusters

Hi All,
We have a 2 node cluster running SQL Server 2000 on Windows 2000 which
needs replacing. The nature of our business is 24 hour operation, so
the downtime to do such needs to be as small as possible.
We have a new cluster ready and waiting in our data centre that is
built on Windows 2003 with SQL Server 2000.
Our issues are:
=B7Configuring all the applications to the new Cluster Name / IP
Address - In the past we have found things hard-coded
=B7Migrate all the data (~100GB) over to the new MSA
=B7Smallest downtime possible
The idea's we have come up with already are:
=B7Frigg DNS to point the old cluster name to the new cluster name and
then migrate all the applications to the new name as time permits.
=B7Rename the new nodes as <NAME>3/4 and add these into the existing
cluster; however the MSA is directly connected to Nodes 1/2.
=B7Remove 1 node from the old cluster, add a new node in, fail-over to
new node, remove 2nd old node, add new node, however I'm thinking
this may not work?
Another consideration is that we use SecurePath on the MSA's so this
could be a PITA.
Does anyone have any other suggestions which we could consider?
Thanks
Well, since you asked.
You could do a minimally disruptive replacement by replacing each node with
one of the new nodes. Uninstall SQL from the "other" node, evict the node,
add the node, run the SQL nstaller to install and configure SQL on the new
node. Wait for maintenance window and do a failover test. Repeat with the
other node.
The other process I use to migrate systems is to run a custom log ship
script (they aren't that hard to write, google will point to some nice free
examples.) to get them ready. Do a final log backup and put the old
databases into norecovery mode. Do a final catch up and go live on the new
system. Patch DNS (hint, use the SRV record type). and go. I can switch
over a typical server with 10-30 databases with less than 10 minutes of
downtime this way.
Geoff N. Hiten
Senior Database Administrator
Microsoft SQL Server MVP
"Steve" <SMaxwell@.NationalExpress.com> wrote in message
news:1160476240.405910.76230@.e3g2000cwe.googlegrou ps.com...
Hi All,
We have a 2 node cluster running SQL Server 2000 on Windows 2000 which
needs replacing. The nature of our business is 24 hour operation, so
the downtime to do such needs to be as small as possible.
We have a new cluster ready and waiting in our data centre that is
built on Windows 2003 with SQL Server 2000.
Our issues are:
Configuring all the applications to the new Cluster Name / IP
Address - In the past we have found things hard-coded
Migrate all the data (~100GB) over to the new MSA
Smallest downtime possible
The idea's we have come up with already are:
Frigg DNS to point the old cluster name to the new cluster name and
then migrate all the applications to the new name as time permits.
Rename the new nodes as <NAME>3/4 and add these into the existing
cluster; however the MSA is directly connected to Nodes 1/2.
Remove 1 node from the old cluster, add a new node in, fail-over to
new node, remove 2nd old node, add new node, however I'm thinking
this may not work?
Another consideration is that we use SecurePath on the MSA's so this
could be a PITA.
Does anyone have any other suggestions which we could consider?
Thanks

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