installed with either the SQL Server Installation Wizard through a command prompt or with Sysprep
for automated deployments with minimal administrator intervention.
SQL
Server 2012 supports upgrade from the following versions of SQL Server:
- · SQL Server 2005 SP4 or later
- · SQL Server 2008 SP2 or later
- · SQL Server 2008 R2 SP1 or later
Run the SQL Server Upgrade Advisor for SQL Server 2012. The Upgrade Advisor is a tool
included with SQL Server 2012, or it can be downloaded directly from the Microsoft website. It
analyzes the installed components on the SQL Server instance you plan to upgrade to ensure
the system supports SQL Server 2012. The Upgrade Advisor generates a report identifying
anomalies that require fixing or attention before the upgrade can begin.
SQL Server 2012 can now be installed on the Server Core, which is an installation option of
Windows Server 2008 R2 SP1 or later. Finally, database administrators also have the option to upgrade
an existing installation of SQL Server or conduct a side-by-side migration when installing SQL Server
2012. The following sections elaborate on the different strategies.
The In-Place Upgrade
An in-place upgrade is the upgrade of an existing SQL Server installation to SQL Server 2012.
When an in-place upgrade is conducted, the SQL Server 2012 setup program replaces the previous
SQL Server binaries with the new SQL Server 2012 binaries on the existing machine. SQL Server data is
automatically converted from the previous version to SQL Server 2012. This means data does not have
to be copied or migrated.
Picture shown below is an in-place upgrade on a SQL Server 2008 instance running on Server 1. When the upgrade is complete, Server 1 still exists, but the SQL Server 2008 instance and all of its data is upgraded to SQL Server 2012.
In-Place Upgrade Pros and Cons
The in-place upgrade strategy is usually easier and considered less risky than the side-by-side migration
strategy. Upgrading is fairly fast, and additional hardware is not required. Because the names of
the server and instances do not change during an upgrade process, applications still point to the old
instances. As a result, this strategy is less time consuming because there is no need to make changes
to application connection strings.
The disadvantage of an in-place upgrade is there is less granular control over the upgrade process.
For example, when running multiple databases or components, a database administrator does not
have the flexibility to choose individual items for upgrade. Instead, all databases and components are
upgraded to SQL Server 2012 at the same time. In addition, the instance remains offline during the
in-place upgrade. This means if a mission-critical database or application or an important line-ofbusiness
application is running, a planned outage is required. Furthermore, if a disaster transpires
during the upgrade, the rollback strategy can be a complex and time-consuming affair. A database
administrator might have to install the operating system from scratch, install SQL Server, and restore
all of the SQL Server data.
Side-by-Side Migration
The term “side-by-side migration” describes the deployment of a brand-new SQL Server 2012
instance alongside a legacy SQL Server instance. When the SQL Server 2012 installation is complete, a
database administrator migrates data from the legacy SQL Server database platform to the new SQL
Server 2012 database platform.
The greatest benefit of a side-by-side migration over an in-place upgrade is the opportunity to build
out a new database infrastructure on SQL Server 2012 and avoid potential migration issues that can
occur with an in-place upgrade. The side-by-side migration also provides more granular control
over the upgrade process because you can migrate databases and components independent of one
another. In addition, the legacy instance remains online during the migration process. All of these
advantages result in a more powerful server. Moreover, when two instances are running in parallel,
additional testing and verification can be conducted. Performing a rollback is also easy if a problem
arises during the migration.
However, there are disadvantages to the side-by-side strategy. Additional hardware might need to
be purchased. Applications might also need to be directed to the new SQL Server 2012 instance, and
it might not be a best practice for very large databases because of the duplicate amount of storage
required during the migration process.
More to come...stay glued!!!!!!!