Tape capacity on 3590 H11

[tonty]

Could anyone shed some light on this. Every evening we back up one huge library that is around 500Gb in size using standard os/400 command SAVLIB, we don't secure the access paths so that makes it around 300Gb backed up. Now for the weird bit, this all fits onto 1 20Gb/40Gb tape... How?

I know we're definitely backing everything up as recently we had to clear the library and restore the whole lot from tape.

Tape Drive 3590 H11
OS/400 version v5r2m0

Any help would be appreciated as this is really confusing me.

Regards,
Tony.

 

[DukeSSD]

Are you sure you only use 1 tape?
It seems the H11 has a 10 cartridge auto loader.
One 3590 H11 extended length tape is 60GB native or 180GB compressed, so 10 tapes would give you 1.8TB.

http://www-8.ibm.com/storage/pdf/G225-6824-05.pdf

 

[p5wizard]

Depending on the "compressibility" of the data in your "huge library", the 3590 H11 might still be able to grind it all (300GB) down to 60GB on just one extended length cartridge...
If that library contains a lot of text files, or zero-filled blocks, that would not surprise me.


HTH,

p5wizard

 

[tonty]

This really does fit on a single tape and it really is a 20Gb/40Gb tape! I can only assume that the data is highly "compressible".

Thanks for taking the time to comment.

Regards,
Tony.