DLT IV Tape capacity

[Todd Lilley]

Hello All;

We installed a new Ultrium Drive and are consolidating some of our DLT IV tapes from older drives. We have two servers using a Compaq 20/40 drive and DLT IV media. We also have several other servers with HP VS80 40/80 drives and DLT IV media.

My question is can the older DLT IV tapes from the 20/40 drives hold up to 80 GB when used in the VS80 drives?

Any help would be great.

Thanks

[Jeff Wilkins]

I would think so. It is all a matter of compression. I have seen DLT IV tapes marked FULL from 115GB to 34GB. Mind you the tapes holding only 34GB are compressed system images and the other various UNIX backups.

[Todd Lilley]

Thanks Jeff, for the quick reply.

So you are saying all DLT IV tapes should be able to hold up to the 80 GB because it is the drive and BU software that determines the compression rate?

Thanks

[Marino Meloni_1]

hello,

first, the DLTvs80 is only Read compatible with DLT4000.

This mean that if you want to use your DLT iv cartridges in your VS80, you need to degauss them



http://h18000.www1.hp.com/products/storageworks/dltvs4080/qa.html

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50057

marino

[David Ruska · Accepted solution]

The DLT IV tapes are:
20GB native in a DLT4000
35GB native in a DLT7000
40GB native in a DLT8000
40GB native in a VS80 (but different tape format than DLT8000)

On top of this, the drive had hardware compression which has compression ratio of 2 to 1 on average, which means you typically double the above numbers to determine how much data from the host will fit.

Your compression results will depend on your specific mix of data.