How to make room for an additional distro

[Avi Greenbury]

Pongo Pan wrote:
> On Fri, 2012-09-14 at 00:23 +0100, Avi Greenbury wrote:
> > Pongo Pan wrote:
> > > 
> > > Install gparted, the Gnome partitioner, and shrink the primary partition
> > > you have now (may take a long time: run this overnight) and then add an
> > > extended partition in which you can make as many logical partitions for
> > > more distros as you like.
> > 
> > This will not work; you cannot resize the partitions on a disk that is
> > in use, so you cannot resize the partitions on a disk containing the
> > operating system you are using.
> 
> You're right, of course.  I've so seldom had a machine with only one
> partition on it that it didn't occur to me that you can't resize from
> within a partition.  

It's not partitions, it's whole drives. If your OS is on /dev/sda1,
then you can't modify any volume on sda from within it[0]; the problem
is of altering the partition table that defines a mounted partition.

You could resize the volumes on /dev/sdb if you're booted off
/dev/sda, but that's getting towards an edge case.

> > You could boot off a live CD (such as Parted Magic), but it seems a
> > bit of a convoluted process - boot off a live CD to resize partitions,
> > then boot off a different live CD to install the system - when the
> > Mint install CD will be able to perform both tasks.
> 
> I still prefer to use a specialist live CD for partitioning: you get all
> the additional utilities like disk cloning, hardware checking, etc. in a
> nice environment and a full-fledged gparted is easier to use and simpler
> to understand than the cut-down version that comes with ubiquity and its
> clones.

You get GParted in the Ubuntu LiveCDs, I'd be surprised if you don't
get it on Mint; other than that I can't argue that you *shouldn't* use
two CDs for an installation, it just seems a weird method to suggest
to someone who apparently doesn't want to do any disk cloning or
hardware checking, just install an OS.

-- 
Avi

[0] Unless you use LVM, but then you're still not modifying a volume
on /dev/sda you're modifying a volume in your VG.