On Mon, 2005-08-08 at 19:03 -0700, Ajay Sharma wrote:
> Hi,
> This might sound like a n00b question, but I've honestly never done this
> with a Linux machine... (it is running Centos3)
It's not a noob question. It comes up regularly.
> How would you do it?
I regularly do this on Linux and Solaris (and should be applicable to
just about any other System-V UNIX flavor -- especially step #3) using
the following procedure.
I recommend you do it from run-level 1 (or even init=/bin/sh), but it's
not totally necessary (it all depends on what files are open and/or what
is running).
1. Slice (partition) new disk and create new filesystems
NOTE: If you're using filesystem labels (e.g., e2label), we sure you
enter them appropriate under #4 below. If you configure software RAID,
remember your configuration files.
2. Create a new mount point, say /newroot, and mount new filesystem
tree under /newroot
NOTE A: You do _not_ need a 1:1 filesystem setup, you can change your
filesystem organization if you wish.
NOTE B: Also remember that /newroot/tmp, if a separate filesystem,
should be chmod 1777, although #3 might correct this anyway.
3. Copy all existing data as follows ... (pretty much universal to
all System-V UNIX flavors) ...
for i in / /fs1 /fs2 ...; do
cd $i
find . -mount | cpio -pmdv /newroot$i
done
You can make this one line with:
# for i in / /fs1 /fs2 ...; do cd $i; find . -mount | cpio -
pmdv /newroot$i; done
NOTE A: The list of filesystems should be the _original_, not the new
ones. Using the "-mount" (sometimes "-xdev" on other implementations)
option to find does not cross filesystems, hence why you pass the
existing filesystems. The new tree will be populated as appropriate.
NOTE B: "Sparse files" may be expanded after this operation and take up
more disk space, depending on the filesystem(s) in use.
4. Modify filesystem (e.g., /newroot/etc/fstab), bootloader
(e.g., /newroot/etc/grub.conf or lilo.conf), etc... as appropriate,
including any LVM/MD disk organization.
6. Re-install bootloader (e.g., GRUB/LILO) to new disk
NOTE: You _may_ need to boot the distro's CD and recovery mode after
you remove the former disk for proper BIOS-Linux device disk mapping.
I've been able to do so in LILO without, but GRUB always seems to never
likes the fact that my mappings don't line up until I make them actual
(so I typically use the rescue CD).
--
Bryan J. Smith b.j.smith at ieee.org http://thebs413.blogspot.com
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