3.6.0 MxDB for SQL Server Installation and Administration Guide (5697-7088, December 2007)

Chapter 8: Upgrade Production SQL Servers 123

General Machine Upgrades

This procedure applies to the following types of upgrades:

• Operating system, include service packs and hotfixes

• Firmware

• Third-party software

These upgrades may require a reboot; however, you can minimize

machine downtime by perform a rolling upgrade. In this scenario, you will

need to fail over the Virtual SQL Server from the primary node, and then

upgrade that node while the Virtual SQL Server resides on the backup

node. Clients will see a small downtime from two failovers (a failover to

the backup node before the upgrade, and a failback after the upgrade)

instead of a full upgrade downtime as in a non-clustered environment.

The procedure first upgrades the backup node and then upgrades the

primary.

Upgrade the Backup Node

Complete these steps:

1. Ensure that all virtual SQL servers are active on their primary nodes.

2. Disable hosting on the backup node.

3. Apply the upgrade (for example, a win2k service pack).

4. Enable hosting on the backup node.

Upgrade the Primary Node

Complete these steps:

1. Disable hosting on the primary node and verify that all virtual hosts

have moved to a backup node.

2. Apply the upgrade.

3. Enable hosting on the primary node. By default, Virtual SQL Servers

are set to

NOFAILBACK and will remain on the backup node. If you

want a Virtual SQL Server to fail back to the primary node, you will