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BP1013 Best Practices for Enhancing Microsoft Exchange Server 2010 Data Protection and Availability 7
2 Exchange Server data protection options and
challenges
The traditional elements that should be identified before the definition of a business continuity plan
(BCP) of any service are:
• Recovery Point Objective (RPO), which defines the maximum acceptable amount of data loss
measured in time
• Recovery Time Objective (RTO), which defines the duration of time within which the service of
your application must be restored
• Features, constraints, and potential of the technology underlying the infrastructure to be
backed up and/or recovered
The RTO/RPO figures are an output of an exercise unique to each organization, commonly identified
as business impact analysis (BIA), which evaluates the balance between the possible threats, the costs
for implementing the recovery mechanisms and the risk acceptance of downtime or unavailability of a
service.
A common set of limitations, valid across any line-of-business or corporate application protection
strategy, with an impact in the process used to implement the RTO/RPO requirements into the
technologies, are the following:
Backup window Represents the period of time when backups are allowed to run. In general
this is selected based on the usage pattern of the line-of-business/corporate
application (for example, 24x7x365 or 9 to 5) with the goal of minimizing the
contention of users access and backup tasks on the application resources.
Backup frequency Determines how often the backups are scheduled to run. It represents the first
factor to evaluate when the RPO is planned and influences the RTO because
the amount of time required to recover a service is based on the number of
backup sets that have to be brought back online.
Data retention Indicates the length of time that the backup sets are to be kept intact. It
influences how far back in time the RPO can be. The main concerns around
data retention are the legal and privacy aspects of it, not only the business
related ones.
While the RTO/RPO variables are decided by the business needs of each organization, we will
investigate the backup and recovery options that a business could choose for the mailbox database
portion of a service based on Microsoft Exchange Server 2010.
Due to the many distinct elements of a Microsoft Exchange deployment, we decided to narrow our
scope to the area where the user data is permanently stored, which means the Exchange servers
identified by the Mailbox role. We should remember that from a holistic point of view, concerns about
the restore of a service based on Exchange technologies must include, but are not limited to, the
following elements: