Compression/dedupe ratio

  • 3 December 2021
  • 3 replies

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I want to use Commvault to backup 10 laptops.

The files used are :

  • Vidéo : .MOV, MP4, .RAW, .BRAW, AVCHD, BOO, DOO, TBL, 
  • Editing files:  .FCP ou .SRT
  • Audio : .MP3, WAVE, AAC

Could I use the deduplication and compression on these files? If yes then what will be the ratio?



Best Regards,



Best answer by Stuart Painter 3 December 2021, 15:34

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Hi @BenLee 

Thanks for the question and welcome to the Community!

You can of course set compression and deduplication on your laptop clients, this is likely the best and most efficient way to protect these clients.

Compression and deduplication not only reduce storage costs, but also network transmissions and backup job durations are also reduced.

Some of those file types are already highly compressed and won’t benefit much from further compression. Where you will save is in deduplication if similar files are seen across more than one of those laptop clients.

It is difficult to predict what sort of compression and dedupe ratios are achievable as this is totally dependent on the content being protected.

If the whole client is protected, then very high ratios in 90% are achievable since there are lots of duplicated data across similar client types. 

However, if you are only looking to protect certain files and folders, then it really depends on how much data is duplicated to understand what potential savings might be.



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Hello Stuart,

Thanks for your reply.

So based on the file types that I mentionned above (video/audio/editing), do you have a sizing tool or an equation that can give the client a clear ratio of the capacity that he will gain ?

Best Regards,


Userlevel 7
Badge +15

Hi @BenLee 

It really depends on the duplication probability of the files, since compression may not achieve much of a saving with those file types.

Please take a look at Optimize Storage Space Using Deduplication for an explanation on how deduplication works.

In summary, we take a data block for a certain size, e.g. 128 KB and generate a signature for that data block. If that same 128 KB data block is seen elsewhere, then it is considered a duplicate and not written to storage, a reference to the original unique block is recorded instead.

So, it’s next to impossible to provide certainty for deduplication savings without knowing the data.