Chapter 10. Advanced features for storage efficiency 415
A download window opens that shows all of the files in /dumps and its subfolders on a 
configuration node. You can filter the list by using the “easytier” keyword, select the dpa_heat 
file or files that are analyzed, and clicking Download, as shown in Figure 10-9. Save them in 
a convenient location (for example, to a subfolder that holds the STAT executable).
Figure 10-9   Downloading Easy Tier heat data file: dpa_heat files
You can also specify the output directory. STAT creates a set of HTML files, and the user can 
then open the index.html file in a browser to view the results. Also, the following CSV files 
are created and placed in the Data_files directory:
/SM590000<panel_name>_data_movement.csv
/SM590000<panel_name>_skew_curve.csv
/SM590000<panel_name>_workload_ctg.csv
These files can be used as input data for other utilities. 
For more information about how to interpret STAT tool output and CSV files analysis, see IBM 
System Storage SAN Volume Controller and Storwize V7000 Best Practices and 
Performance Guidelines, SG24-7521.
10.2  Thin provisioned volumes
In a shared storage environment, thin provisioning is a method for optimizing the usage of 
available storage. It relies on the allocation of blocks of data on demand versus the traditional 
method of allocating all of the blocks up front. This method eliminates almost all white space, 
which helps avoid the poor usage rates (often as low as 10%) that occur in the traditional 
storage allocation method where large pools of storage capacity are allocated to individual 
servers but remain unused (not written to).
Thin provisioning presents more storage space to the hosts or servers that are connected to 
the storage system than is available on the storage system.