How to move my / partition

[Chris Tyler]

On Tue, 2010-02-16 at 14:29 +0000, Timothy Murphy wrote:
> I want to move the / partition on a (very ancient) Fedora-12 desktop
> from one SCSI disk to another (/dev/sdb3 to /dev/sda6),
> because the second disk is showing some signs of sickness.
> 
> Is there any safe way of doing this while the machine is running?
> Unfortunately the CD drive does not appear to be working,
> and the machine (an Asus-P2B-LS) does not support booting from USB.
> 
> I could download and install something like Knoppix,
> if it is possible to boot from it with grub?
> 
> Any help or suggestions gratefully received.

Hi Timothy,

If your / filesystem is on a logical volume, which is the default for
F12 installations, you can move it easily:

- Add the new disk.
- Partition the disk (optional but recommended). One partition is fine,
or if you're going to also boot from this disk, then create a new /boot
partition as well. (fdisk)
- Make the new partition a physical volume (PV). (pvcreate)
- Add the PV to your volumg group (VG). (vgextend)
- Tell your system to migrate your data off the old PV (pvmove)
- When complete, tell the system to take the old PV out of the VG
(vgreduce).
- Optional - if desired, remove the PV metadata from the old PV
(pvremove).

Except for physically adding and removing the drives, these steps can be
performed while the system is running, either from the command line or
using the system-config-lvm GUI.

Finally, set up your /boot partition and reset your grub configuration,
and you should be good to go. As when performing any disk
administration, backups are your safety net.

-Chris