Tape Bacup Question

Did it say that it backed up 130 gig of data to the tape, or that the tape had 130 gig of data written? It could be that the compression routines used were able to squeeze alot of white space out of your files from the hard drive - hence being able to back up 130 gig of hard drive data onto a 80 gig tape. Check the properties of the tape, it will tell you total tape capacity, tape used and tape empty.

Wil,
The spec 40/80 is relative and assumes a 2:1 compression with the larger number, provided its done in native mode to Native mode. Its still quite possible to get a better ratio the 2:1 though. If you have a large text file for example that is not compressed (Perhaps for performance reasons) it might gat a 5:1 - 6:1 - 10:1 or better compression ratio. Some files that are compressed already, might actualy get bigger. Bottom line, that figure they give you, assumes a 2:1 average. The lower of the two numbers is what you can expect with out compression. Something to consider is that compression isnt a free ride, where you get extra storage you pay for in performance. I often run my DLT's in uncompressed format as its much quicker to seek and restore files. Thats another consideration if your utilizing a tape library for off-line storage.

Pete