No compression with Deduplication option? (Exception)

[Jeff_Cohen]

I recieved this error on our first Deduplication Option backup, software compression is set in the job options.

BackupThe job has been configured for either data encryption or software compression, or both. The job is also targeted to a device that is capable of data deduplication. Encryption and compression of the backup data can prevent much of the data from being deduplicated.

Is this an issue? I didn't read anywhere you can't have compression turned on on deduplicated sets.

[pkh · Accepted solution]

You cannot use software compress and encryption with dedup because compressing or encrypting the data will render the deduplication process ineffective.  However if you need to either compress or encrypt the data, you can enable compression and encryption in the dedup folder itself.  See these documents

http://www.symantec.com/docs/TECH127779

http://www.symantec.com/docs/TECH124682

[Jeff_Cohen]

So you just cannot have the compression option in the job set when using a deduplicated volume? Not sure why it doesn't just grey that option out then..

I have done the one (set compression=1), the backup does appear compressed. Is there any way to tell if I need to re-run the full backup with the compression option set to nothing in the job?

[pkh]

It is not that you cannot use software compression with a dedup folder.  It is just that compressed data might not dedup properly.

[teiva-boy]

The dedupe engine was bolted on to Backupexec as an afterthought.  Thus what you would like as a greyed out feature, was not implemented.

In the order of operations, from the client, the beremote.exe starts to backup data, and it passes through the dedupe engine off to the media server.

You can enable compression and.or encryption on the BE agent or within the PDCONF file on each client.  If you did it on the agent, the PureDisk dedupe engine would receive data that couldn't be deduplicated anymore (e.g. because it's already pre-compressed or unique via encryption).  

This is why you need to edit the PDCONF on the client or media server, so that compression is applied prior to the dedupe engine doing it's thing, but AFTER the beremote.exe does its thing.  If it's done on the media server, it would apply to all jobs, where as you can do it individually as needed within the PDCONF for client-side dedupe.