[PLUG] Disk partitioning confusion

[David]

On 11/01/2013 10:07 PM, John Jason Jordan wrote:

<snip>

> I started with Palimpsest, which sees it (/dev/sdc), but can't seem to
> do anything with it. So I installed Gparted, which offers to create
> partitions, but fails. My confusion started when Gparted asked me if I
> wanted a primary partition or an extended partition. In the end it
> didn't matter, because Gparted failed to create either kind of
> partition. Google has utterly failed to explain the difference between
> primary and secondary to me. There is also the matter of GUID
> partitions, which I also can't get a clear understanding of.

I can't offer any assistance with Palimpsest; I don't use it and fdisk 
and parted have worked just fine for me so far.

What I can offer is a bit of information about the partition types and 
partition tables.

The disk partitions, as you know, segment the available space on a drive 
into smaller chunks of space. Initially, the primary partition was where 
the operating system was stored and how the system booted. There can 
only be four primary partitions on a drive, and only one of them as 
"active". Because this was seen as a limitation, by converting the 
fourth primary partition to be an extended partition and using logical 
partitions it became possible to have up to seven partitions on a drive.

The GUID partition table (IIRC) is the way a partition table is written 
to the disk and read by the hardware on boot. The original partition 
table was the MBR (I think), and was constrained to the four partitions 
mentioned above and cannot support filesystems above a certain size.

This is mostly from memory and may have some gaps or inaccuracies in it, 
but hopefully this provides a bit of insight for you.

dafr