Is partitioning required?

[Liam Proven]

On 12 June 2011 15:32, Tony Pursell <ajp at princeswalk.fsnet.co.uk> wrote:
> On Sun, 2011-06-12 at 08:34 -0400, Rashkae wrote:
>> On 06/12/2011 03:45 AM, Robert Spanjaard wrote:
>> > I just installed a new harddisk. Because I was planning to use it as a
>> > single large volume, I forgot to partition it. I just clicked Format in
>> > the Disk Utility, and it works.
>> > But now, "sudo fdisk -l" shows the following information:
>> >
>> > ---
>> > Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
>> > 255 heads, 63 sectors/track, 121601 cylinders
>> > Units = cylinders of 16065 * 512 = 8225280 bytes
>> > Sector size (logical/physical): 512 bytes / 512 bytes
>> > I/O size (minimum/optimal): 512 bytes / 512 bytes
>> > Disk identifier: 0x00000000
>> >
>> > Disk /dev/sdb doesn't contain a valid partition table
>> >
>> > Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
>> > 255 heads, 63 sectors/track, 121601 cylinders
>> > Units = cylinders of 16065 * 512 = 8225280 bytes
>> > Sector size (logical/physical): 512 bytes / 512 bytes
>> > I/O size (minimum/optimal): 512 bytes / 512 bytes
>> > Disk identifier: 0x00021241
>> >
>> >     Device Boot      Start         End      Blocks   Id  System
>> > /dev/sdc1   *           1      121601   976760001   83  Linux
>> > ---
>> >
>> > Disk dev/sdb is the new harddisk.
>> > Disk /dev/sdc is a different harddisk, where I did create a single large
>> > partition before formatting.
>> >
>> > Both disks are working fine, but still, I wonder if I should have created
>> > a partition table first.
>> >
>> Not strictly necessary, but a very good idea nontheless.  It can be
>> helpful, for example, if you have a boot sector that bootloaders can
>> install on.  Also, without a partition table, other low level disk
>> utilities or OS may, at some point, simply overwrite parts of the hard
>> drive without warning (as they would assume the hd is blank)
>>
>
> Have a look at it with gparted, and use that to put a partition on it,
> which will be /dev/sdb1.  Formatting the disk probably just put it into
> 512 byte blocks.  Before you can write to it, sensibly, you need a file
> system on it, say ext4, but it could be FAT32, ntfs, ext3 or any other
> file system recognised by the OS.

Be careful!

While this advice is correct, it will erase the disk & you will lose
everything on it, effectively irretrievably.

You /can/ use an unpartitioned disk if you wish, as others have said.
It's just slightly risky, if something decides to try to make it
bootable or something, tries to manipulate the nonexistent boot record
or partition table and trashes your filesystem.

I'd advise copying any data off it, repartitioning as one big primary
ext4 volume, and then putting its contents back.


-- 
Liam Proven • Info & profile: http://www.google.com/profiles/lproven
Email: lproven at cix.co.uk • GMail/GoogleTalk/Orkut: lproven at gmail.com
Tel: +44 20-8685-0498 • Cell: +44 7939-087884 • Fax: + 44 870-9151419
AIM/Yahoo/Skype: liamproven • MSN: lproven at hotmail.com • ICQ: 73187508