What happens if I partition from a live cd?

[Leslie Vincent]

I'm trying to modify some Linux labs for a class I'm teaching so that 
students can work from home on their non-Linux system using the Fedora 
6 Zod live CD on their Windows-based PCs.

One lab has them running fdisk to create a partition, though, and the 
last thing I want is to have them do something that's going to mess up 
their PCs.  Is there a way to have them play with running fdisk off the 
live CD without it affecting their PC's actual hard drives?

I'd play with it myself but I'm at home and don't have access to a 
system that I'm willing to rebuild if I mess up my own hard drive!

Thanks to anyone who can answer this.

[J. Hartline]

Leslie Vincent wrote:
>  I'm trying to modify some Linux labs for a class I'm teaching
> so that 
>  students can work from home on their non-Linux system using the Fedora 
>  6 Zod live CD on their Windows-based PCs.
>
>  One lab has them running fdisk to create a partition, though, and the 
>  last thing I want is to have them do something that's going to mess up 
>  their PCs.  Is there a way to have them play with running fdisk off 
>  the live CD without it affecting their PC's actual hard drives?
>
>  I'd play with it myself but I'm at home and don't have access to a 
>  system that I'm willing to rebuild if I mess up my own hard drive!
>
>  Thanks to anyone who can answer this. 
The only thing I can think of by what you describe, is not actually 
writing the changes, which is documented and is the 'w' option in the first
fdisk menu, otherwise you can probably use small 8MB or 16MB flash 
disks, or simply nit run any fdisk commands at all which doesn't seem 
like a solution.

The really only best way is to have a empty hard drive, and do fdisk 
operations on it, providing you are writing changes.

J. Hartline

[Jane Dogalt]

--- Leslie Vincent <lvincent(a)dtcc.edu&gt; wrote:

>  I'm trying to modify some Linux labs for a class I'm teaching
> so that
>  
>  students can work from home on their non-Linux system using the
>  Fedora 
>  6 Zod live CD on their Windows-based PCs.
>  
>  One lab has them running fdisk to create a partition, though, and the
>  
>  last thing I want is to have them do something that's going to mess
>  up 
>  their PCs.  Is there a way to have them play with running fdisk off
>  the 
>  live CD without it affecting their PC's actual hard drives? 
qemu?

i.e.

qemu-img create /tmp/fakebits.img 100G
qemu -boot d -cdrom /dev/livecd -hdc /tmp/fakebits.img -m 256

(booting the livecd virtually from within the livecd.  Make sure to
make the fakebits device one that is nonexistent on teh real system,
just in case someone thinks they are typing in the virtual host, but
are typing in the real host).  That is assuming qemu is on the livecd. 


Or you could create an empty file, associate it with a loop device, and
partition that perhaps.

-dmc/jdog


>  
>  I'd play with it myself but I'm at home and don't have access to a 
>  system that I'm willing to rebuild if I mess up my own hard drive!
>  
>  Thanks to anyone who can answer this.
>  
>  
>  
>  
>  
>  --
>  Fedora-livecd-list mailing list
>  Fedora-livecd-list(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-livecd-list
>   


 
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[Joel Andres Granados]

Jane Dogalt wrote:
>  --- Leslie Vincent <lvincent(a)dtcc.edu&gt; wrote:
>
>    
> > I'm trying to modify some Linux labs for a class I'm teaching so that
> >
> > students can work from home on their non-Linux system using the
> > Fedora 
> > 6 Zod live CD on their Windows-based PCs.
> >
> > One lab has them running fdisk to create a partition, though, and the
> >
> > last thing I want is to have them do something that's going to mess
> > up 
> > their PCs.  Is there a way to have them play with running fdisk off
> > the 
> > live CD without it affecting their PC's actual hard drives?
> >     
>
>  qemu?
>
>  i.e.
>
>  qemu-img create /tmp/fakebits.img 100G
>  qemu -boot d -cdrom /dev/livecd -hdc /tmp/fakebits.img -m 256
>
>  (booting the livecd virtually from within the livecd.  Make sure to
>  make the fakebits device one that is nonexistent on teh real system,
>  just in case someone thinks they are typing in the virtual host, but
>  are typing in the real host).  That is assuming qemu is on the livecd. 
>
>
>  Or you could create an empty file, associate it with a loop device, and
>  partition that perhaps.
>
>  -dmc/jdog
>
>
>    
> > I'd play with it myself but I'm at home and don't have access to a 
> > system that I'm willing to rebuild if I mess up my own hard drive!
> >
> > Thanks to anyone who can answer this.
> >
> >
> >
> >
> >
> > --
> > Fedora-livecd-list mailing list
> > Fedora-livecd-list(a)redhat.com
> > https://www.redhat.com/mailman/listinfo/fedora-livecd-list
> >
> >     
>
>
>
>   
>  ____________________________________________________________________________________
>  We won't tell. Get more on shows you hate to love 
>  (and love to hate): Yahoo! TV's Guilty Pleasures list.
>  http://tv.yahoo.com/collections/265 
>
>  --
>  Fedora-livecd-list mailing list
>  Fedora-livecd-list(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-livecd-list
>     
Vmware is another possibility.  Download Vmware from 
http://www.vmware.com/download/ (I understand you have to be 
registered).  Once the students have a virtual machine installed in 
their windows box (There is an virtual machine creation wizard that they 
can follow) they can start the fedora live cd by inserting the cd in the 
computer drive ( The virtual machine has to be configured to look at the 
physical drive and not something differente like an iso image,  but 
thats usually the default configuration so I would suppose there needs 
to be no additional configuration.). 
This setup allows them to fdisk all they want and not be in danger of 
damaging their box.

Regards
Joel

[J. Hartline]

>  Jane Dogalt wrote:
> >
> >
> > Or you could create an empty file, associate it with a loop device, and
> > partition that perhaps.
> >
> > -dmc/jdog
> > 
This is perhaps a good idea I did not think of, when I think fdisk I 
simply think physical
disks. This is what I would go for, this assumes I suppose learning how 
to create files with dd and
mounting an arbitrary file to loop.

Thanks jdog.

[Joel Andres Granados]

Jasper Hartline wrote:
> > Jane Dogalt wrote:
> >>
> >>
> >> Or you could create an empty file, associate it with a loop device, and
> >> partition that perhaps.
> >>
> >> -dmc/jdog
> >>
>  This is perhaps a good idea I did not think of, when I think fdisk I 
>  simply think physical
>  disks. This is what I would go for, this assumes I suppose learning 
>  how to create files with dd and
>  mounting an arbitrary file to loop.
>
>  Thanks jdog.
>
>  -- 
>  Fedora-livecd-list mailing list
>  Fedora-livecd-list(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-livecd-list 
I managed to use the
fdisk command in the fedora liveCD.  Here is what I 
did:

1.  su - (become root)
2. dd  count=2000 if=/dev/zero of=fileName (basically means to copy 2000 
blocks from the zero device to the fileName,  The zero device simply 
spits out \0 characters)
3. mkefs -T ext2 fileName (created a ext2 file system so I could easily 
loop back mount it)
4. mount -o loop fileName /mount/path (mounted the file on the /mount/path)
5. fdisk /dev/loop0 (usually the loopback mount is located in 
/dev/loop0,  you can find out where the mount was made with the `mount` 
command)
6. have fdisk fun :)

I checked my original partitions and the process didn't affect them.  
But I would test it first just to be sure :) 
Im using the livecd in a vmware machine.

Regards
Joel.