Is this right? I put 55GB on a dds-3 12/24 tape

[pk28]

HiEverybody,

I just bought a Seagate STD224000N DDS-3 12/24 tape drive and used MSbackup to put a folder containing 55GB of information onto a dds3 tape. I expected to use three tapes for this job but it only took one!

Is it possible to get a 4:1 compression on these drives? I am sceptical. I tested the tape by restoring to another location and all the information seemed to be there.

The only possible explanation that I can think of for this is that the information I am storing is primarily TGA image files. they are usually 1.5 MB in size and about 1/3 of them are Alpha channel output, meaning that they are mostly black images...I believe black images compress to a smaller size in Jpegs but I would not expect this with the tape drive information.

Has anyone experienced this? any help would be appreciated

PK28

 

[tapedrivedoctor]

Hi,
the drive specification is compression ration 2:1
It is very unlikely to get 55GB on one tape. I would check the data on the other location by accessing random files.

 

[kinetic7]

Highly compressible files can give you more than a 2:1 compression ratio. 4:1 is extremely unusual, though and I don't have a lot of faith in NT backup either. If the drive came with backup software, I'd try using that just to be sure. Tapeware and Backup Exec both work well with DDS. Of course, it couldn't hurt to try restoring the backup to a file so you can make sure it's all there.