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Part V: Enterprise Data Management
■ (^) Log shipping provides redundancy at the database level and not at the SQL Server
instance level like SQL Server failover clustering. Log shipping applies only the
changes that are either captured in the transaction log or the initial full backup of
the log shipping database. Any database objects such as logins, jobs, maintenance
plans, SSIS packages and linked servers that reside outside the log shipping data-
base need to be manually created on the warm standby server.
■ (^) When the primary server fails, any transactions made since the last time the
transaction log backup was shipped to the warm standby server may be lost and
result in data loss. For this reason, log shipping is usually set to occur every few
minutes.
■ (^) The switch between primary and warm standby server is not transparent. A series
of steps must be manually executed by the DBA on the warm standby server, and
front-end application connections must redirect the data source and reconnect to
the warm standby server.
■ (^) After the primary server is repaired, returning to the original confi guration may
require manual DBA intervention.
If these issues are acceptable, log shipping to a warm standby server can be an excellent
safeguard against downtime.
Best Practice
Ideally, the primary server and the warm standby server should be in different locations so that a
disaster in one location cannot affect the other. In addition, log shipping can place a large demand
on a network every few minutes while the transaction logs are being moved. If the two servers can be
connected with a private high-speed network, log shipping can take place without affecting other
network users and the bandwidth they require.
Defi ning Log Shipping
In SQL Server 2000, log shipping was available only in Developer and Enterprise Editions.
Starting with SQL Server 2005, log shipping was made available in Workgroup, Standard,
Developer, and Enterprise Editions. Now, in SQL Server 2012, log shipping is available in
Enterprise, Standard, Business Intelligence and Web editions. Developer Edition can be used
only for development purposes and not for production.Microsoft provides a simple-to-use Log Shipping Wizard to create a maintenance plan to
back up, copy, and restore the transaction log from the primary server to the warm standby
server every few minutes. Log shipping has built-in monitoring that makes it easy to main-
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