DASH Copy from a non-deduped primary copy

I know this does not answer your question, but what appliance are you planning to use? 

Hi, they are using Huawei X8000.

Is the end goal to get better dedup rate when compared to Commvault?

So, unsolicited advice. I have tried and burned by this in the past.

My experience is that, almost never (tested two hardware appliances well known)  hardware deduplication appliances will give better than CV Dedup.

Also, your primary has to be dedup for you to maintain a secondary copy dedup. You can indeed disable dedup, however your secondary copy will then not be dedup. 

Obviously each environment and design/layout change but personally the concept and proposition of dedup appliances specifically in conjunction with CV isnt not something I would recommend. 

"DASH Copy transmits only unique data blocks, which reduces the volume and time of an Auxiliary Copy job by up to 90%."

Source: https://documentation.commvault.com/11.40/commcell-console/optimize_storage_space_using_deduplication.html

Hi,

I’m aware that’s not the main concern here, but which products have you tried? I’m aware that each vendor is unique, but as far as I know good ratio still can archived and in case of large data volume such devices can be more performance and storage efficient.

Hardware deduplication can also provide additional layer of defense, with native immutability and lack of access to data itself. I’ve seen a company where such configuration saved them from ransomware ransom.