[Tech] Come raddoppiare (a vostro rischio) la capacita' dell'hard disk

Se vi piace vivere pericolosamente, su The Inquirer viene descritto un metodo per spremere dal vostro hard disk un mucchio di spazio extra.



Alcuni esempi:

Interesting results to date:

Western Digital 200GB SATA

Yield after recovery: 510GB of space



IBM Deskstar 80GB EIDE

Yield after recovery: 150GB of space



Maxtor 40GB EIDE

Yield after recovery: 80GB



Seagate 20GB EIDE

Yield after recovery: 30GB



Unknown laptop 80GB HDD

Yield: 120GB

Naturalmente, dal momento che non esistono cose come i pasti (o i Gigabyte) gratis, anche qui ci sono delle avvertenze e delle controindicazioni, come riportato in questa e-mail a commento dell'articolo:

Regarding article "Unused space on hard drives recovered?"



I am the "Linux SATA guy".



First, users are usually amused to learn that the capacity of modern hard drives is _unknown_, until it goes through the factory's qualification tests. The 120GB hard drive you purchased may have been physically identical to a 250GB hard drive, but simply it only passed qualification at 120GB.



Intel does the same thing with processors. A 3.0Ghz processor may be sold as 2.4Ghz, simply because it didn't pass qualification at 3.0Ghz but did at a lower clock speed.



Second, in the ATA standard there is a feature known as the "host protected area". This area is accessible from any OS -- but it requires special ATA commands in order to make this area available to the OS.



Third, all hard drives reserve a certain amount of free space to use for reallocation of bad sectors. These "spare sectors" are free space on your drive... completely unused until your hard drive starts finding problems on the physical media.



So this is old news :) Although the host-protected area (HPA) can be used for insidious purposes such as DRM/CPRM that is completely hidden from the users, most of the "invisible free space" exists for a purpose -- either it's spare sectors for bad sector remapping, or its capacity that didn't pass factory qualification, that you don't want to use anyway.



Feel free to edit/reproduce/publish this email.



Jeff Garzik



Not speaking for my employer, speaking as an Open Source guy

Si può fare, quindi, ma non è detto che dopo siano sempre e solo rose e fiori.



Fonte: The Inquirer.