[ALUG] How to use pvcreate?

[Chris G]

On Sat, Nov 03, 2007 at 05:16:54PM +0000, Chris G wrote:
> OK, so I have cleared everything off my /dev/sda (except, presumably,
> the MBR) and all is well still, Fedora still boots and my Windows
> guest virtual machine is still working.
> 
> How do I now set up /dev/sda using LVM?  As I understand it the
> sequence is to create a Physical Volume using pvcreate, then a Logical
> Group that uses the Physical Volumes I have created and then I create
> a logical volume in the Logical Group.
> 
> The problem is that I don't understand how you tell pvcreate what disk
> it is to use.  The 'synopsis' on the pvcreate man page says:-
> 
> SYNOPSIS
>    pvcreate   [-d|--debug]   [-f[f]|--force   [--force]] [-y|--yes]  [-h|--help]  [-t|--test]
>    [-v|--verbose] [--labelsector]  [-M|--metadatatypetype] [--metadatacopies#copies]  [--meta-
>    datasizesize]  [--restorefilefile] [--setphysicalvolumesizesize] [--version] [-Z|--zeroy/n]
>    PhysicalVolume [PhysicalVolume...]
> 
> Which doesn't seem to give much clue as to what disk it uses,
> PhysicalVolume is (as I understand it) the name that pvcreate gives to
> the chunk of disk you want to use, so what disk does it use?
> 
It's OK, although the man page wasn't very clear the example was, a
PhysicalVolume is simply the same name as the device, so I just say:-

    pvcreate /dev/sda2

So now I have created my PhysicalVolume and I have created a Logical
Group that is just that PhysicalVolume I'm now stuck trying to set the
size of a VolumeGroup to use all of the space.

If I just say:-

    lvcreate VolGroupA2

I get an error saying "Please specify either size or extents (not
both)", there seems no way to specify 'all' and I can't find anything
that tells me what the parameters to --size mean.

Help!?  :-)

-- 
Chris Green