Disaster Recovery & Business Continuity for SQL Servers Through a Standby Approach

le="margin-bottom: 0in; line-height: 150%;"A simple and inexpensive solution to recovering from
align="justify">Introductionfailure is to take backups of all your databases.
Businesses of all sizes must take backup and disasterOut-of-the-box Microsoft SQL Server disaster
recovery seriously. As companies grow and datarecovery operation allows for Native SQL Server
becomes more and more prevalent, users of allBackups that can take full, differential or transaction
types, either internal or external, require access to alllog backups of a database. Another disadvantage to
this information. This is essential at a time when evenSQL Server Native Restore procedures involves high
the smallest business may find operations impossibledowntime. In cases of disastrous failure, time is a
with any single point of failure. With the launch of MScrucial factor. Unfortunately, significant delays are
SQL Server 2005, MS SQL Servers are becomingintroduced when trying to find the correct backup
increasingly popular for use in mission criticalfiles and locations from which to restore databases.
environments. With such important dependencies onTypically, when these restores need to be
software solutions, recovering from failures is crucialperformed, the inability to restore is something most
for business continuity.organizations cannot tolerate.
To initiate movement towards redundancy and failureAutomated Standby Solution
protection, Microsoft offers SQL Server Log ShippingA Standby Server is a server where the data from
(SQL Server 2000 and 2005) and SQL Serverthe primary databases is restored periodically using
Database Mirroring (SQL Server 2005) in its corescripts, Microsoft Log Shipping or through a third
products. In addition to Microsoft, third partyparty software. It acts as a hot standby which can
vendors, including Microsoft Gold Certified Partnersbe promoted to a primary role if the primary server
such as Sonasoft, provide enhanced softwaregoes down so that business operations continue to
solutions that simplify disaster recovery scenariosfunction. An automated standby solution bridges the
through easy to use Management Console andgap between a highly expensive Failover Clustering
automating most of the manual steps. Thesesolution and time-consuming Native SQL Server
components are focused on minimizing downtimeBackups and Restores. An automated standby
while maximizing data retention in the event ofsolution provides a high-availability solution, protecting
catastrophic failure.data from hardware and software failures as well as
High Availability Solutions for SQL Serversfrom human errors.
Failover ClusteringSonasoft Standby Solution
Microsoft Clustering enables users to prevent againstThe Sonasoft Standby Solution builds
hardware failures by stringing redundant hardware,easy-to-manage standby plans that effectively
called nodes, together through a central clusterreplicate your data without interfering in normal
manager that coordinates load balancing and databusiness operations. Because the Sonasoft Standby
activity. Microsoft SQL Server supports bothSolution transfers only data that has changed since
active-active and active-passive cluster environments.the last backup as well as uses high speed
As protection against hard disk failure, RAIDcompression through the network to the standby
configurations are also common. However, from aserver, data transmission can be handled by a
performance standpoint, this significantly slows downlow-bandwidth T1 or a low-cost DSL line. When
I/O in the subsystems due to writing the data todisaster strikes, role switching is just one click away,
multiple disks at the same time. Again RAID option isas a series of complex database operations are
to protect against any hard disk failure but it cannotperformed in the background to switch the
prevent site disasters.destination server(s) to the primary role.
In direct contrast to this storage dependency, using aSonasoft’s product, SonaSafe for SQL Server
Standby solution prevents against hardware,contains a unique architecture that not only creates
software and storage failures. Standby servers oreasy to use backup tasks and schedules, but allows
databases are normally installed on unique, usuallyfor efficient and simple recovery options all while
geographically independent, SQL Servers which serveminimizing chances of data loss.
as a barrier to failures of any type. SQL ServerConclusion
Clustering environments are more cost-intensiveStandby servers are a cost-effective and viable way
compared to the Standby option. The primary reasonfor businesses to maintain SLA and business
for this is the high hardware and softwarecontinuity efficiently. While other solutions do exist,
requirements. On the other hand, a Standby serverthey are limited by either being error-prone or failing
does not have any special hardware requirementsto protect against site failures. One can deploy
and is simply a software solution to meet disasterstandby servers using third-party software that utilize
recovery needs. An additional cost, LAN connectivityeasy to use interfaces for a fraction of the cost
is required between SQL Server cluster nodes toassociated with some alternatives as discussed
send and receive what is called a heartbeat signal,above. Also, these standby servers can be functional
among other communications.for reporting or testing purposes.
SQL Server Native Backups/Restores