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BP1013 Best Practices for Enhancing Microsoft Exchange Server 2010 Data Protection and Availability 21
The combination of the results for these series of tests helped us evaluate the cost of creating Smart
Copy snapshots for an entire business day (identified by 8 hours) and to assess their variation while the
amount of online users was variable. At the same time we verified if and how the occurrence of a
critical situation would affect this status.
That test design should help in predicting the behavior in real world environments with either a
constant or a variable number of connected users and different rotations of work hours.
6.1 Time taken results and analysis
Because the time taken to create a Smart Copy with EqualLogic and ASM/ME is very short, we
measured it by observing the events recorded in the Application Event Log of the mailbox database
servers.
Exchange Server service components (the Information Store and ESE engine) generate an extensive
track of messages describing the course of preparing the required metadata for the VSS backup, the
activation of a Shadow Copy instance, and the beginning of the database freeze. They also generate
the reverse-ordered messages indicating the closure and end of each opened task.
Figure 6, Figure 7, and Figure 8 show the elapsed time between the beginning of the Shadow Copy
activation and successful completion. The time taken for the database ‘freeze’ part of the process is
also shown.
Figure 6 Time taken for Smart Copy snapshot of one volume under increasing workload (percentage of 5000
concurrent users)