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sql server clustering : Create SQL cluster on 2003



Amy Lewis
4/20/2005 11:34:07 AM
I have 2 2003 servers each running a separate copy of SQL. I have purchased
a external storage Dell Powervault running RAID 5 to serve as the shared disk
space. I would like to create a SQL cluster with these 2 machines. Each SQL
server has databases that will need to be moved to the shared space. What is
the easiest way to accomplish this?

I was thinking I would need to do backup my databases from both SQL servers.
Create a cluster in 2003 cluster management
Uninstall SQL server from both SQL servers
Install SQL server as a virtual server from one of the 2003 servers.
Restore the SQL databases to the shared disk space

Amy Lewis
4/20/2005 1:15:04 PM
Thanks for the response. I have actually talked with Dell about this and
given the small volume of SQL database activity - they recommended this.

I have not configured my PowerVault yet - would Raid 1 be better relating
to performance? My current 2003 servers have a single RAID 5 configuration -
and the databases are stored in the normal c:\program files\..... and it
seems to be working fine for us. We only about about 20 databases - all
small (the largest is 500M) and all with less than 20 users connected at 1
time.

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Geoff N. Hiten
4/20/2005 2:58:26 PM
First, your configuration is unsupported. A cluster must be purchased as a
cluster, not just assembled ad-hoc from components that may or may not be on
the cluster Hardware Compatibility list in order to be a supported
configuration. Some storage vendors will certify the entire platform if you
purchase installation services along with the storage device.

Second, your RAID-5 Powervault will run very slowly in a cluster. RAID-5
has significant overhead for writes. Normally a caching controller can
mitigate these issues but with clustering, all SCSI controllers for shared
storage must disable write cache. Since you have the PowerVault divided
into a single array, you will have to install SQL onto the Quorum partition,
again an unsupported configuration. Note that Clustering will work at the
RAID container level, not at the logical partition level. Data and
transaction logs will be on the same physical device so there goes another
bit of performance and recoverability. The whole purpose of SQL Clustering
is to increase availability. I don't see how this configuration will help
reach that goal.

I would talk to my Dell representative about their certified cluster
offerings rather than pursue this path.

Since you did ask for how to do something instead of whether it should be
done, here goes. Create a cluster and install an instance of SQL onto the
cluster (likely a named instance since I would guess that the local
machine(s) already use a default instance). After that, it is a simple
matter to move the databases as you would between any two SQL servers.
Windows 2003 Server has a really great clustering wizard that keeps you from
building a non-functional cluster. Once that is working, you can easily
install SQL clustering according to the instructions in BOL.

HOW TO: Move Databases Between Computers That Are Running SQL Server
http://support.microsoft.com/default.aspx?scid=kb;en-us;314546

Geoff N. Hiten
Microsoft SQL Server MVP
Senior Database Administrator


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Geoff N. Hiten
4/20/2005 4:26:33 PM
I am assuming a PV 220S with 14 slots.

2ea RAID-1 drives for Quorum and MSDTC (36GB 15KRPM) Normal best practices
has them apart but with your small scale combining them should be safe.
2ea RAID-1 drives for Logs (73GB 15KRPM)
2ea RAID-1 drives for Data (146GB 15KRPM)

That leaves 8 slots for future expansion. Make sure you have blanks so the
airflow works correctly. You can adjust the sizes of the drives to meet
your needs, but try to keep the Quorum and Logs drives at 15KRPM. The speed
definitely makes a difference. Since you are in a cluster configuration,
the physical location of the drives in the individual slots makes no
difference. This will give you a decent performing system that is also
pretty reliable and recoverable.

Geoff N. Hiten
Microsoft SQL Server MVP



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