Reload Analyzer Manual

Tandem Reload Analyzer Manual Page 33 of 42
blocks in
average
chain
organized file, the file will have one long chain. This number is
calculated by taking the average blocks in a chain and dividing
it by the total data blocks.
Table 2-1. Values in Chain Length Histogram
File < 100 MB
File > 100 MB
1
1 - 25
2 - 10
26 - 50
11 - 25
51 - 100
26 - 50
101 - 250
51 - 100
251 - 500
> 100
> 500
Counting Data Chains
A data chain is a set of logically contiguous data blocks. Reload Analyzer counts the
data chains in a file by:
 Opening a file for unstructured read-only access using bulk I/O
 Counting data and index block types
 Analyzing the length of the data block chains as well as the frequency of the
chaining
Understanding Data Chain Information
The length and the number of chains are the most important factors when deciding
whether to reload a file. One long chain in a file is better than many short chains. If the
file has many small chains, the file probably should be reloaded.
The following example shows the Data Chain Information sections of two files. This
first example is the Data Chain Information section of File A.