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Veritas backup stops after 40 GB on a DAT72 Tape

Rob van Meeuwen
Occasional Contributor

Veritas backup stops after 40 GB on a DAT72 Tape

Last week, we ran into a problem.
We are using Veritas Backup 10 with an tape drive of HP (C7438A) and use DAT72 tapes. Last week the data exceeded the 40 Gb. When the backup up reaches the 40 GB, it ejects the tape and asks for a new tape.

How can I fix this, because the tapes should suppose the amount of 72 GB (with compression; which is on also)?

Any help will be appreciated!
3 REPLIES
TTr
Honored Contributor

Re: Veritas backup stops after 40 GB on a DAT72 Tape

The dat72 drive and dat72 tape native capacity is 36GB. This means that on the tape when it gets full, you have 36GB of COMPRESSED data. Now how much UNCOMPRESSED data is this? It depends on your data, it looks like you data does not compress much that's why you get about 40GB.
The DAT72 states 72GB capacity assuming a 2:1 compression ratio. That means if the data compresses 2:1 you could fit 72GB of data compressed to 36GB in a dat72 tape.
Rob van Meeuwen
Occasional Contributor

Re: Veritas backup stops after 40 GB on a DAT72 Tape

So, does this means that we should use tapes with higher capacity?

And, this is a different kind of question, is it possible to speed it up? It will take more than 12 hours to finish the backup of this amount of data.
Rob Leadbeater
Honored Contributor

Re: Veritas backup stops after 40 GB on a DAT72 Tape

Hi,

If I were you I would ditch the DAT drive and get hold of an LTO drive.

Much higher capacity and much better performance. Something like an LTO-2 Ultrium 448 would probably be adequate (200GB native capacity)

http://h10010.www1.hp.com/wwpc/us/en/en/WF04a/12169-304612-3446236-3446236-3446236.html

Cheers,

Rob