6.5.1

If you run the SAN management software on a virtual machine, you gain the benefits of a virtual machine,
including failover with vMotion and VMware HA. Because of the additional level of indirection, however,
the management software might not see the SAN. In this case, you can use an RDM.
Note Whether a virtual machine can run management software successfully depends on the particular
storage system.
SAN Storage Backup Considerations
Having a proper backup strategy is one of the most important aspects of SAN management. In the SAN
environment, backups have two goals. The first goal is to archive online data to offline media. This
process is repeated periodically for all online data on a time schedule. The second goal is to provide
access to offline data for recovery from a problem. For example, database recovery often requires a
retrieval of archived log files that are not currently online.
Scheduling a backup depends on several factors:
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Identification of critical applications that require more frequent backup cycles within a given period.
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Recovery point and recovery time goals. Consider how precise your recovery point must be, and how
long you are willing to wait for it.
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The rate of change (RoC) associated with the data. For example, if you are using
synchronous/asynchronous replication, the RoC affects the amount of bandwidth required between
the primary and secondary storage devices.
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Overall impact on a SAN environment, storage performance, and other applications.
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Identification of peak traffic periods on the SAN. Backups scheduled during those peak periods can
slow the applications and the backup process.
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Time to schedule all backups within the data center.
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Time it takes to back up an individual application.
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Resource availability for archiving data, such as offline media access.
Include a recovery-time objective for each application when you design your backup strategy. That is,
consider the time and resources necessary to perform a backup. For example, if a scheduled backup
stores so much data that recovery requires a considerable amount of time, examine the scheduled
backup. Perform the backup more frequently, so that less data is backed up at a time and the recovery
time decreases.
If an application requires recovery within a certain time frame, the backup process must provide a time
schedule and specific data processing to meet the requirement. Fast recovery can require the use of
recovery volumes that reside on online storage. This process helps to minimize or eliminate the need to
access slow offline media for missing data components.
vSphere Storage
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