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BP1014 Enhancing SQL Server Protection using Dell EqualLogic Snapshot Smart Copies
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In Figure 4 we show the impact on CPU utilization during the backup process.
Figure 4 – CPU utilization impact when creating SQL Server backup using native backup utility
3.2.1 Analysis and conclusion
As expected, we saw a significant increase in CPU load on the system during the time that the backup
utility was creating the backup. We also measured a 30% average increase in application response time
during the same period.
Based on the test results it is evident that running backups during peak periods will have direct impact
on:
 The SQL Server® host performance: backup processing CPU cycles may impact other product
workloads.
 Database performance: increased query response times.
As illustrated above, this extra load on the production host is what database administrators want to
avoid, hence organizations try to find backup windows or periods of low activity during which backups
can be completed. Using off-host backups as described earlier in this paper the CPU cycles consumed
by backup processing can now be used by the SQL Server® workload.
3.3 Testing SQL Server snapshot processing time and impact
In this series of tests we measured the impact on server and database performance when running the
SQL Server® native snapshot utility to create point-in-time copies of a database.
The snapshot utility in SQL Server® 2008 allows you to create point-in-time copies of a database. SQL
Server® snapshots are read-only. Multiple snapshots can exist for a single source database. The
snapshots must always reside on the same server instance as the source database. Each database