98 ILM Library: Techniques with Tivoli Storage and IBM TotalStorage Products
Often temporary files can be deleted on a cyclical basis, for example, files in temporary
directories that are older than 90 days (or whatever policy you want to set), or archiving older
log files. It is important to monitor the amount of storage space used for temporary files, and
check if the growth rate is constant or variable. It should be proportional to used storage
growth rate.
5.5.4 Actions for stale files
In “Classify valid data and verify stale files” on page 92, TPC for Data generated reports with
the amount of storage last accessed and last modified in different periods of time.
Analyzing this report, we can select some file systems to be migrated to a lower-cost tier
storage. In the first report, described in “Last access date report” on page 92, files last
accessed between the past 3 and 9 months are good candidates to be evaluated and
migrated to a lower tier. Files last accessed over the past 9 months may be considered
candidates for migration to the lowest-cost storage or archived to a sequential media (for
example, optical or tape).
In the second report, described in “Last modification date report” on page 94, files last
modified between the last 6 to 9 months may be considered candidates for migration to a
lower-cost storage. But a further study should be done to check which storage they are using
and which application is using them. If they are located in high-performance-cache-write
disks, then evaluate whether storage with this characteristic is still needed for these files.
5.5.5 Actions to RDBMSs space
In “Reporting database unused space” on page 96, TPC for Data generated reports with the
amount of storage used by RDBMS databases, datafiles free space and segments wasting
Check the storage space unused by databases and the amount of free space remaining in
datafiles and report them to database administrators. This space can be used to satisfy future
needs and growth. When more space is needed, expand the database in the unused space
instead of allocating more disks. If data files have free space, reclaim it with procedures to
reduce the databse size. For example, check with database administrators if it is possible to
export and import the database to reduce the storage space.
5.6 ILM - Return on investment (ROI)
We should expect an ILM project to generate a return on investment; but how can this be
calculated? ILM is a service level solution, and an ROI calculation should consider savings in
many areas of investment—hardware, software, services, and support costs, among others.
The main ROI factors focus on improvements in application availability, storage utilization,
and personnel productivity. Some or all of the main elements of ILM can be implemented to
meet the data management needs:
򐂰 Tiered storage management
򐂰 Long-term data retention
򐂰 Data lifecycle management
򐂰 Policy-based archive management
Organizations should invest in information management solutions to be able to grow storage,
and back up and move data without impacting access. They should have a centralized control
for backup, restore, copy services, and a common pool for unallocated storage. They need

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