Accelerated Flash Compression Estimator Tool

The Accelerated Flash Compression Estimator Tool (hafdc2_estimator.exe) samples existing data and estimates a compression ratio.

By using the Compression Estimator Tool before storing data to an FMC, you can estimate the saving percent, and the compressibility of your data. The tool samples data that is in a file or volume that you specify and calculates a compression ratio using the same compression algorithm as the storage system and FMC. By calculating a saving percent for the actual data, you can confirm the effect of accelerated compression with high precision. The Compression Estimator Tool must be installed on the server host that has access to the data you want to sample. For details about how to get or use the Compression Estimator Tool, contact customer support.

The following is an example of executing the Compression Estimator Tool:

Best practice is to use the value of Saving % (Except Zero data) in the formula for estimating FMC capacity. The following explains the items in the example:

• SAMPLE: The number of data samples. In this example, the value is 3,000. To shorten the time required for the estimate, the Compression Estimator Tool extracts random samples from the target data. Therefore, the result output by the tool is an estimated value. The actual savings might vary depending on the situation.

• Uncompressed Bytes: The data size before compression. The value is approximately 24 MB in the example.

• Compressed Bytes: The data size after compression. The value is approximately 16 MB in the example.

• Saving %: The data-size saving rate after compression. The value is 34.32% in the example.

• Saving % (Except Zero data): The data-size saving rate with all zero pages excluded from the data before compression. The value is 32.57% in the example.

• Compression Ratio: The ratio of data size compression. In the example, the data size after compression is assumed to be 1, and the ratio of data size compression is 1.5.