Capacity of LTO-2 media

[Bob Rekieta]

LTO-2 media is advertised as being 200 GB Native. Is this 200 * (1024 ^3) or 200 * (1000 ^ 3)?

Is this documented anywhere?

Thanks

[Jean-Luc Oudart]

I'm not sure this is there,
but here's the page
http://h18006.www1.hp.com/products/quickspecs/11529_div/11529_div.html

Then, usually use the compressed format and compression ratio will vary much depending on type of data. so 2:1 compression is an average !

Regards
Jean-Luc

[Bob Rekieta]

Thanks for the info, however, I don't see anywhere on that page where a GigaByte is defined. It is quite a difference if the tape will hold 200,000,000,000 bytes or 214,748,364,800 bytes of data in uncompressed mode.

[Stuart Whitby]

This is rarely an exact capacity anyway. Differences in tape lengths mean that two tapes are rarely identical, which makes your question a moot point. As to whether it would be 1024 or 1000, it depends whether the brochure was written by a technician or a salesman.

Given that it's rare not to use compression and that compression is variable depending on the type of data being written, I wouldn't worry too much about this.

Sorry I can't give a more precise answer though :/

[Leif Halvarsson_2]

Hi,
I belive 200 * (1024 ^3) is correct. I am not exact sure but DataProtector uses this value for calculating media space.

In any case, you can't rely on this as an exact value, there will always be minor differences from one media to another.

[Marino Meloni_1]

http://h10025.www1.hp.com/ewfrf/wc/genericDocument?lc=en&cc=us&docname=c00004116

here are some more info but not related especialy to the LTO technology

[abhijeet_7]

It is 200^(1024^3).

regards
abhik

[Fred Ruffet]

If "GigaByte" is explicitely mentionned then it should be 2*(1024^3)... Except if package is done by marketing services :)
On my Ultrium-2 LTO tape is mentionned 200GB* and * tells : "assuming 2:1 compression", which one, you'll never reach.

Note that your backup software may use a part of this place to store information on what it saves, so you wil not get such a volume. Except with dd.

Regards,

Fred