Copy to tape without deduplication

[Alvaro]

Hi

I have a quick question.

I have a primary backup of 30 TB on disk where a deduplication ratio of 0.89 is applied.

I want to make a second backup copy to tape and I need to size the number of drives to make the copy correctly in the required time.

On tape there is no possibility of applying deduplication.

My question is:
Do I need to undo the deduplication done on disk to size the drives I need to copy to tape?

That is, when copying my primary backup (which occupies 30 TB deduplicated on disk) to tape, I would need to copy only 30 TB or would have to copy with tape jobs 30 / (1-0.89) = 272 TB

Thank you.

[Egor Yakovlev]

Hi Alvaro,
Tape data savings are more about compression, rather than deduplication. Veeam backups are compressed by default(unless you change it's setting) and when you copy those backups to the tape, there is not much data savings with tape compression applied afterwards. We are not decompressing backups prior tape job execution, so having 30TB Veeam backups on disk, you should plan 30TB to be transferred on tape.
/Thanks!

[Andreas Neufert]

Using double compression (Software + Tape) could cause more space usage on Tape. If the backup files are compressed, it makes sense to deactivate the compression at the tape job.

[Alvaro]

But when I backup to disk besides compression I also have deduplication.

But on tape I only have compression, there is no deduplication, so you should undo the deduplication ratio.

So the question is:
To size the amount of data to copy from disk to tape, do I have to undo the deduplication rate applied to the data?

I am not talking about compression, but about deduplication, since deduplication is not supported on tape

Thank you

[Egor Yakovlev]

"Backup to Tape" job transfers backup files, and does not really care if they are deduplicated or not. File is a file and tape will have it totally same, without rehydrating deduplicated blocks during the process.

[Alvaro]

Perfect. Problem solved1

Wonderfull forum...All of you reply very quickly!!

Thank you!!!

Best regards!