How to format mac os x? i lost 100gb

[Theo]

I met a strange problem. I erased my hard drive 250 GB ,2 partitions -> 200 GB and 50 GB .After formatting I find myself with only 149 GB please can any one suggest hard disk tool and tell me how can i do better format my os and has anybody an idea that I found my 100 GB lost ?pleas help me

[timon]

Disk Utility / volume with the manufacturer's references DD (it begins with the real capacity of SD, wanted to make you think about it real capacity). The intellectuals who make them for Standardization 1 KB is 1000, for the computer is 1024. My DD sold for a 80 GB on my old laptop is really a 74.5 GB So on DD 1 TB you realize what you have thought but that you lack
As they do ever make mistakes, they have added a code that is true for computers. Manufacturers take the most flattering for them. So you make your choice when playing. On this basis, we find more easily.

[SalVatore]

"Partition" means that you will "sausage" your hard drive into several independent pieces. So if you partition your hard disk of 500 GB in 2 partitions of 250 GB, it is as if you were in some way 2 hard drives of 250 GB! And instead of seeing a hard drive icon on your desktop, you will get 2!. Of course you can adjust the size of your partitions according to their destinations.
What are the advantages of partitioning? Firstly, this allows you for example to install OS X on a partition and get a score by example for storage of files, video files, personal files and why not make another partition for encoding your video?.
Another advantage, if for example You must reinstall OS X days, you no longer have to erase your entire hard drive: You just simply clean the single partition OS X. .. What time saver! All your personal files will be ready to use on their dedicated partition!
And if you still need the "Classic" proposed by OS X 10.4 Tiger, it goes without saying that you are going to install Tiger on another partition LEOPARD!

Another advantage is that you can create a partition on an external hard drive to accommodate a clone of your main OS X volume, and start on this clone to use your software optimization and maintenance (such as TechTool Pro, "" Drive Genius or Disk Warrior "...) from this partition to treat sores on your OS X system without having to boot from the bootable CD of these applications. (Start on a CD is longer than the boot another partition.)
NB: In this case, it is preferable to install a clone on one partition to another hard drive than where your main OS X partition (an external hard drive firewire or USB 2 for example).

Of course, it is not necessary or even imperative to partition their hard drives, it's just an interesting possibility which is offered by Apple and OS X and can facilitate the use of his Mac every day. Can you see if this can help and organize your workspace as you see fit. You decide.
Some "purists" you might declare that "partitioner" has become obsolete and useless on OS X, but these allegations are devoid of common sense.

Discover in the first application "Disk Utility" which allows you to initialize (erase), training and possibly (if you want, because it is not mandatory) to partition your hard drive.

The application "Disk Utility" can be found on the DVD of installation of Apple operating system. So, QED, you have an application "Disk Utility" on your installation DVD of Mac OS X.

As against the golden rule to remember when deciding to initialize and partition a hard drive is ALWAYS start on either the DVD installation (For this, after inserting your OS X DVD in the Mac, restart holding "C" key ...), or on another hard disk with a bootable OS X partition (clone)!

- Boot from the installation DVD if you plan to initialize / partition the hard disk, then install OS X from the installation DVD on a hard disk initialized / partitioned.
- Boot from another hard disk (clone) if you intend to initialize / partition the main hard disk, then clone the boot partition (from the other hard disk) to a partition on your main hard drive.

Once re-started either on DVD or on another hard drive, you can get down to serious ...

Here is how to initialize, format and partition a hard drive (everything is actually at the same time).


1) Start of course MUST be on your installation DVD of Mac OS X (button "C" key), or on another hard drive bootable OS X.

2) If you use the Install DVD OS X, an installation window appears on the screen, click "Use English as main language, then in the menu" Utilities "in the bar of the Finder choose" Disk Utility ".
If you start on another hard drive in OS X, launch the application "Disk Utility" located on this drive.

3) This software will launch

Your internal hard drive (s) and external (s) appear in the left column.
Select the drive you want to initialize, format and partition by simply clicking once on the disc icon in the left column (*). The characteristics of the disk appear in the bottom of this window.

(*) You can not initialize the whole hard disk on which you started ... but only the other partitions that start (if there are partitions).


Then click on the tab "Partition".

4) A new window will appear
In this window you will enter all the information about the format and number of partitions you want, and their respective sizes:

[Solomon]

if your hard drive allows and if your Mac allows you to boot into OS 9 (this is increasingly rare), you can also install OS 9 on one of your partitions. For this we need the option "Install managers Mac OS 9 (this option is then all partitions on your hard drive and not just this one partition.)

If this box is unchecked, then the hard disk can not be used on a Mac that can boot into OS 9! (an old iMac G4 for instance).
PS: If you do not see this box in the tab "Partition" after selecting a hard disk in the left column, then it is that hard drive / Mac is incompatible with OS 9.

Repeat this for each of your partitions. Also note that you can, in the partition window, play with the sliders between each partition to increase or decrease the size of the latter.

Under Leopard, it is even possible now to change on the fly the size of a partition. If you want to change the size of a partition on your hard drives, you can do without the initialize (thus preserving all the data contained therein). You can reduce the size of a partition for a new insert in the space thus created. However, there are some limitations: for example it is impossible to enlarge a partition that could take the place vacated by the former. This would move the space, something impossible to do with "Disk Utility". In addition, an Intel Mac is required, since the partition type should be GUID.

Personally, I much prefer to use "Drive Genius" or "IPARTITE" for this type of operation, as these two programs are more flexible, offer more opportunities and are less "expeditious" (see below).

You're done? A name, format and size were given to each of your partitions? Then just click the "Apply" button at the bottom right.