Veritas Storage Foundation Intelligent Storage Provisioning 5.0.1 Solutions Guide, HP-UX 11i v3, First Edition, November 2009

Policies for storage tiers
Storage tier policies determine where every piece of data is stored based on the
business needs of the enterprise and taking into account factors such as:
■ The value of the data to the business
■ The need for access to the data
■ The cost and ease of accessing each storage resource
Storage tier policies allow the movement of data between storage tiers to be
automated when certain criteria are met. For example, you can write a policy to
move customer records that are older than 30 days from high-cost,
high-performance storage to lower-cost, lower-performance storage.
Using Veritas Storage Foundation Web GUI, you can define and implement policies
throughout the network from a central console.
Table 3-2 shows the typical factors that can be taken into account when
implementing policies for storage tiers.
Table 3-2
Storage tier policy factors
DescriptionFactor
Some files are more valuable than others to an enterprise. For
example, losing a day's business transactions is significant but
probably survivable. Losing quarterly or annual closing figures, on
the other hand, might be catastrophic. Losing an entire day's work
is a significant setback for an employee, but losing the finished
product is a much more serious setback for the company.
Availability
Enterprise accounting, security, and regulatory compliance may
require that specific files or types of files be confined to certain
storage devices.
Business
considerations
Different types of data need different levels of I/O performance.
Streamed data requires high bandwidth for data transfer
performance, but moderate I/O request rates are often acceptable.
Transactional data requires high I/O request rates, but the
bandwidth requirements may not be critical if only small amounts
of data are involved.
Expected access
patterns
Applications that run concurrently may compete for I/O resources
unless their data is placed on separate storage devices with separate
access paths.
Load balancing
An ideal policy ensures that files are placed on the most appropriate type of storage
when they are created, and that they are relocated to different tiers of storage
25Tiered storage solutions
Policies for storage tiers