Measures reported by DDomainFileCompTest

The deduplication process divides the data into variable length blocks and calculates a signature for each block. For each signature, the deduplication process determines if any other identical signature exists, and if not, hardware compresses the unique block and writes it to the data pool. If it finds any matches to these signatures, it replaces that redundant block with a pointer to the unique block so that only one copy of that data block exists on disk.

This test monitors the file systems of the Data domain storage system and reports the size of each file system prior to and after compression. In addition, this test reports the percentage of size reduced due to compression for each file system. Using this test, administrators can easily figure out how well a file system has been deduplicated and to what extent the deduplication was successful by merely analyzing the compression ratio of the file systems prior to and after compression.

The measures made by this test are as follows: