hello,

I just bought a 3TB hard drive.
I'd like to configure it in order to be able to use it. From what I understand it becomes more complicated for hard drives over 2TB.
I want to get the most out of it (being able to work with as many operating systems as possible (including xp, for instance), being able to boot on it, having if possible only one partition, etc...).
What am I supposed to do exactly?

Thanks

Here is what I do:
Install XP first to a primary partition using whatever size partition you want for XP.
Create a swap partition. All linux distros can share the same swap.
Create a /data partition for storing your data. All linux distros will share this data partition.
Create a root partition for each distro that you want to use.
Install one distro's grub to the MBR, and use that grub to boot all of your operating systems. This distro should be installed second after XP since it's grub will control the MBR.
For all other distros, either choose not to install grub (or lilo), or install those distros boot loaders to their respective root partitions.

I'm sorry, but I feel you misunderstood me. I wasn't talking about how to install an operating system or boot loader, but rather how to initialize the hard drive and surpass that 2TB limit.

I'd take a look at it with GParted to see what it looks like, then go from there.

I have a 2TB external that came formatted NTFS (which was mildly surprising, since most USB stuff seems to come FAT32).

I split it into two drives formatted with ext3.

So what commands exactly am I supposed to execute in order to format it ?
The disk right now is a mess, I have to reformat it because I tried some things that didn't work.
The disk is empty, there's no data on it, all I need is to format it so that I can use it (I want a ntfs file system, but I think the first issue that needs to be dealt with is the 2TB size limit).

The MBR is limited to 2TB drives. You will need to use a GUID partition table (GPT) and grub2 as the bootloader to boot from the drive. Use parted to create a GPT since the old fdisk tools are not capable. Only 64 bit XP supports GPT.

Well, to bypass it you want to split it into 2 1.5 TB partitions.

Here is a very comprehensive informational article about partitions (if you don't know what partition is or don't know how to do it): http://tldp.org/HOWTO/Partition/

So basically, if I understood correctly, what you're saying is that I can either create a 3 TB gpt partition but then I won't be able to boot on it nor to use it with a 32 bit xp, or I can create 2 1.5TB mbr partitions and then I will be able to use it with windows xp and boot on it. Is that correct ?
Is there no other solution than these 2 ?
Thanks.

What are the command lines to achieve both of these 2 results, assuming I want a ntfs file system ?

Can someone help me with that please ? I'm quite lost and I'd like to start using this new hard drive .

Get a Parted Magic live CD: http://partedmagic.com/doku.php Boot up with the Parted Magic live CD and use it to partition the drive into as many partitions as you desire. Parted Magic can create NTFS partitions, as well as linux (ext3, ext4, etc) partitions.
I suggested Parted Magic because it has a simple graphical interface that is easy to use and works well.
Plus, with Parted Magic you can even browse the web with Firefox while you are waiting for your partitioning tasks to complete!

hello,
it seems you misunderstood my question again. The other answerers understood my question. I'm not asking how to partition a hard drive with a live CD, I'm asking how to format and partition it in order to bypass the 2TB limit.

Please tell me if I'm right about this:
if I understood correctly, what you're saying is that I can either create a 3 TB gpt partition but then I won't be able to boot on it nor to use it with a 32 bit xp, or I can create 2 1.5TB mbr partitions and then I will be able to use it with windows xp and boot on it. Is that correct ?
Is there no other solution than these 2 ?
What are the command lines to achieve both of these 2 results, assuming I want a ntfs file system ?

Thanks

As far as I know that is correct.
As I said, you can create as many partitions as you desire.
I suppose you could use parted to create the partitions. Or, since you can't use gpt partitions with 32 bit XP, you could just use cfdisk to create the partitions. Then use mkfs.ntfs to format the partitions to NTFS.

I suggested the Parted Magic live CD because it can accomplish these tasks easily and intuitively from it's graphical interface.

Okay then I'd rather use the second option, so that I can use my drive from windows xp.
What would be the command line to create a mbr hard drive with two 1.5TB partitions whose block sizes are 8K and whose file systems are ntfs (in both partitions) ?
Thanks

If you use cfdisk, it has a ncurses interface instead of typing commands. Have a look at it and read up on it. When you create a partition with cfdisk, the type 07 is for ntfs. Then you can format the partitions as NTFS with something like:
where sdXY is the partition number.
I am not sure about the 8k block size. I have never worried about block sizes in any of the hard drive that I have partitioned, and it always works ok for me.
When using a command like mke2fs to create ext3/4 partitions, the option is -b for block size. I am not sure if you can use that with mkfs.ntfs, since I don't see that in the man page for mkfs.ntfs http://linux.die.net/man/8/mkfs.ntfs