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chunk commit process during backup job using ddb

  • 22 March 2021
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Hi all,

Is it possible if some explain the process of committing chunks to lib and signature in ddb. I read somewhere that chunk will keep on noting all data blocks even it is repeated. Actually m confused with that statement . Might b my understanding is wrong but need help to understand exactly when ddb signatures will be committed to ddb and when will chunk will get committed ?

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Best answer by Damian Andre 22 March 2021, 21:53

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Hey @Karamveer Singh 

 

I think this video may answer a lot of your questions:

https://commvaultondemand.atlassian.net/wiki/download/attachments/501350567/DDB%20V4%20Gen%202.mp4?version=1&modificationDate=1584463632881&cacheVersion=1&api=v2

 

But the simple version is, if its a new block we’ve never seen before, we store the data in the chunk and comit the signature in the DDB. If its a block we have encountered before, we don’t store the data, but we put a link to where the data is in the chunk exists instead. Think of it like a shortcut or symbolic link. This is why you don’t need the deduplication database to exist to perform restores - the chunks link to the data rather than having to query the database to find out where the data is.

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