We recommend not to use other hardware or software deduplication applications with Commvault Deduplication. This is because using a secondary software or hardware deduplication application on top of Commvault deduplication can incur unneeded performance and resource utilization on systems and provides no further benefit to the already deduplicated data.

For Compression, though Commvault performs Compression before Deduplication, you may see a reduced Deduplication rate if compression is performed by the client.
This may need to test Compression on the Filer vs Compression on Commvault determine what works best for your environment.

Cheers,
Jase