ILM Library: Techniques with Tivoli Storage and IBM TotalStorage Products

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

storage.

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