Facts about How SQL Server 2008 setup works... #3

Setup.exe can be patched dynamically on the fly

One of the drawbacks of the sql server 2005 setup was that if there was any bug detected in the code of the setup.exe , the patching of the setup.exe was difficult and at times next to impossible.

With Katmai, it is possible to patch the setup.exe on the fly due to the following property of the bootstrapping code (setup.exe).

When the setup.exe is called it checks for the presence of the local copy of the setup.exe, In other words it checks if the support files are already installed or not. If it finds the local copy of the setup.exe of the same or greater version, the local setup.exe is launched.

So there are 2 ways to patch the setup process

1) If you have a local share of the sql server 2008 installation media on the disk, you can simply replace the old sqlsupport.msi with the new sqlsupport.msi. This can be useful for enterprise customers which uses the single share of the copy of the media for multiple installation

2) If the setup has been installed then in that case sql support files are already been installed. So in that case we will have to download an addition patch from Microsoft site and install the support files of the version higher than the version of setup.exe. So when the setup.exe of the RTM version is called, it finds a local copy of the support files of the version higher than RTM and as explained previously, it launches the setup.exe of the local copy which is the patched setup.exe.

RULES AND VALIDATION CHECKS

With sql 2005, setup performs System Configuration checks (SCC) however with katmai the SCC checks have been further enhanced, there are various rules defined which needs to be met for the successful installation of the sql server.

There are Global Rules checks which apply to all the scenarios (viz install, upgrade, uninstall ...etc) however there are additional scenario specific rule checks which need to be met for the specific scenario to succeed.

Discovery Report

In sql 2005, there were many failure observed since the uninstall of the previous install was not clean and cannot be detected. In Katmai, Discovery report in the setup process can be used to check for the previous failed installation and which should be cleaned up so that they are not the cause of the failure in the new instance. In addition it can also be used to see the existing sql installation on the system and their version.

Generation of the Configuration File

In an enterprise when we need to perform multiple identical installations of the sql server on different system. It can be much beneficial, faster and efficient to use silent quiet installation of the sql server, wherein the entire configuration option are captured in the single configuration file and can be reused multiple time with minimum user intervention.

Each installation of sql server 2008 creates a configuration file which can be used for silent installation in future. In addition we can specifically run the setup process to create the configuration file. The default location of the configuration file which is created is

C:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\Log\<session _ folder>

Parikshit Savjani
SE, Microsoft SQL Server