DELL POWER SOLUTIONS
Reprinted from Dell Power Solutions, February 2006. Copyright © 2006 Dell Inc. All rights reserved.
February 2006
26
DATABASES: SQL SERVER 2005
Enterprise data centers that host business-critical appli-
cations and databases can be at risk from failures and
disasters. Availability and recoverability become crucial for
business operations. Current database availability technolo-
gies vary in their complexity, cost, level of automation,
incurred downtime, and supported distance. A major chal-
lenge for an enterprise is determining the most cost-effective
and least complex solution to help ensure database avail-
ability and meet business needs. Microsoft SQL Server 2005
introduces several high-availability features and feature
enhancements for the SQL Server database platform.
Failover clustering
Failover clustering with Microsoft Cluster Service (MSCS)
is a popular way to achieve high availability for SQL
Server. With MSCS, multiple servers or nodes are linked
to function as a single system and provide an automatic
failover solution. Enterprises are connected to virtual serv-
ers and not physical servers; each active physical server
may host one or more virtual servers.
If one of the physical servers fails because of either a
hardware or software problem, MSCS detects the failure
and moves resources that reside on the failing server—
including the virtual server(s)—to one or more remaining
physical servers. End users connected to the failed server
observe only a momentary delay in accessing its resources
while MSCS restarts SQL Server services on the remaining
server(s) and remaps the virtual server connections.
Installing a failover cluster requires the following:
•
Microsoft Windows® 2000 Server (Advanced Server
or Datacenter Server) or Microsoft Windows Server™
2003 (Enterprise Edition, Datacenter Edition,
Enterprise x64 Edition, or Datacenter x64 Edition)
•
Microsoft SQL Server 2005 (Standard Edition or
Enterprise Edition)
•
Shared storage based on SCSI, Fibre Channe