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40fa-a026-5bfcf076d9b9/SQL2008inHyperV2008.docx) and
Planning, Implementing, and Supporting SQL Server Virtualization
with Windows Server 2008 R2 Hyper-V and Live Migration
(http://download.microsoft.com/download/4/4/D/44DB08F7-144B-
4DF6-860F-
06D30C6CE6E4/SQL%20Server%202008%20R2%20Virtualization%
20Whitepaper.docx)
You cannot use an old Windows NT-style domain for a Windows Server 2008 or
later server. You must be using Active Directory. If your organization is using
older-style domains, you cannot deploy Windows Server 2008/2008 R2 until
your Active Directory infrastructure is upgraded.
By default, Windows Server 2008 and 2008 R2 are more secure than Windows
Server 2000 and Windows Server 2003. Many of its features are not configured,
so there will be additional work involved in the upgrade.
Windows Server 2008 and 2008 R2 support only SAS, fiber channel, and iSCSI. If
you are using older parallel SCSI, you have to upgrade your disk solutions to
support Windows Server 2008.
For more Windows-specific information about how to deploy and upgrade to Windows
Server 2008 and 2008 R2, see
Upgrading to Windows Server 2008
(http://technet.microsoft.com/en-us/library/cc754728(WS.10).aspx) and
Windows
Server 2008 R2 Upgrade Paths
(http://technet.microsoft.com/en-
us/library/dd979563(WS.10).aspx). For information about how to upgrade to Windows
Server 2008 or 2008 R2 failover clustering with SQL Server 2008 R2, see the "Upgrading
Failover Clusters" section in Chapter 4, "High Availability."
Upgrading Multiple Instances
You might have multiple instances of SQL Server 2005/2008/2008 R2 on a standalone
or clustered server. Multiple instances can make the upgrade process more difficult, so
you must consider them before the upgrade. The options are simple: Should all
instances be upgraded in one maintenance window, or should you upgrade them
individually?
Upgrading them all at the same time will minimize overall deployment resources
because you have to schedule only a single outage. But that also means that if anything
goes wrong for any reason, you might have more to fix and deal with, which could
increase downtime. It is a risk versus reward decision.
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Upgrading Very Large Databases
Many SQL Server databases are in the hundreds of gigabytes or terabytes range. This
presents special challenges in any upgrade process because you have to account for
constraints in time and hard disk space when you deal with large amounts of data in a
short window of maintenance time. Databases in the terabyte range can potentially
take days to copy over a network—even the fastest networks. These VLDBs might be
mission-critical databases powering the largest systems in your business and might
tolerate very little downtime. When an upgrade has to occur over a weekend, you
might have to use several techniques and put in many preparation hours to meet the
required time frames for success. You might have to revise the upgrade window if the
upgrade will not fit within it.
When you work with VLDBs, more than any other scenario except perhaps high
availability, careful planning is required to ensure a successful upgrade experience. The
cost of a failure if there is an unexpected issue is much larger because of the time
involved to resolve the issue. For example, if a copy of a database backup file stops half
way through, or if a stored procedure uses discontinued T-SQL syntax, you will lose
time. With an in-place upgrade, you gain more time because you do not have to
physically move the database. However, this upgrade method makes a restore costlier
if there is a serious failure causing you to roll back to the original database. Advance
testing in a full-size test or staging environment is very important in these cases.
For more information about VLDB upgrades involving failover clustering or database
mirroring, see Chapter 4, "High Availability."
Upgrading High Availability Servers
For issues related to high availability features such as clustering, database mirroring,
log shipping, and replication, see Chapter 4, "High Availability." See Chapter 4 even if
you do not use these features for high availability. For example, if you have to upgrade
systems that use replication, even if the upgrade is not for high availability purposes,
you need to review Chapter 4’s information.
Minimizing Upgrade Downtime
For small, simple instances where you can afford maintenance downtime during the
business day, it might not be important to take additional measures to speed up the
upgrade and minimize end-user downtime. But many times, you will want to take the
quickest route to minimize the inconvenience to your business when a business
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application is offline waiting for the upgrade to be complete. For high availability
applications, you might have to take additional measures to absolutely minimize the
downtime. For high availability and VLDB upgrades, see the detailed information in
Chapter 4, "High Availability," which goes beyond the basic information in this section.
The following steps can help minimize the downtime involved in an in-place upgrade
or side-by-side upgrade:
Check the legacy SQL Server versions. Make sure that the legacy instances of
SQL Server 2005/2008/2008 R2 are at the correct service-pack level for an in-
place upgrade. If they are not at the correct level, plan to update them before an
in-place upgrade (see "Setup Requirements for an In-Place Upgrade" earlier in
this chapter).
Make sure that installation requirements are met. SQL Server 2012 Setup
also has Windows and other component requirements (see "Setup Requirements
for an In-Place Upgrade" earlier in this chapter).
Preinstall .NET and Windows components. If you can, install .NET Framework
3.5 SP1 or a later version and Windows Installer (MSI) 4.5 beforehand on the
target server. Both require a restart. For an in-place upgrade, if a restart in
production cannot be enabled except for the upgrade, install them during the
upgrade and not earlier. For a side-by-side upgrade to a separate server,
installing these components before the upgrade will help reduce downtime.
When you run the SQL Server 2012 Upgrade Advisor on a legacy server, a restart
will be required if MSI 4.5 must be installed.
Preinstall Visual Studio 2008 SP1 or a later version. If Visual Studio 2008 is
installed on the server, make sure that it is at the SP1 level (see "SQL Server
Prerequisites Installed by Setup" earlier in this chapter).
Preinstall SQL Server 2012 common components. Install the SQL Server 2012
common components (such as the SQL Server 2012 SQL Native Client) before
the upgrade. Also consider pre-installing the Management Tools if SQL Server
2012 Management Studio (SSMS) is not required to manage SQL Server 2000
instances. (For more information, see Chapter 2, "Management and
Development Tools.")
Select the optimal side-by-side upgrade strategy. In a side-by-side upgrade,
SQL Server databases must be transferred during the upgrade, and several
strategies are available, such as backup and restore, detach and attach, and log
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