Clone root partition

Hi,

I'm trying to compile a comprehensive document on cloning root partitions.
My immediate goal is to clone my current working Linux to external USB HD,
so that I can use it wherever I go.

By comprehensive I mean it should not be as simple minded as

dd if=/dev/hda2 of=/dev/sda2

or

cp -a / /mnt/point

or

tar -p -m cf - / | (cd /mnt/point; tar xf - )

I know they work, but there are so many things have been left out. By
comprehensive, I mean I want to know all relevant things that need to be
considered.

For example for dd, let alone its rigid limitation, if you use it, at least
the 'conv=sync,noerror bs=4k' options should be used: sync,noerror just
means continue and zero fill any error blocks, bs=4k just writes 4k at a
time which will speed things up a lot. For cp, at least 'cp -ax' should be
used.

But there are still much more to it.

First, directories that don't need to copy over, like /tmp, /proc. With
modern Linux that uses udev, the /dev and /sys don't need to be copied
either. Anything else (besides distro specifics like /var/cache/apt/archives)?

2nd, the clone partition should be made bootable, by grub or lilo.

Anything else? Like the concerns of /etc/fstab...

Last, with all the above concerns, how to achieve them with various tools?

Keywords: tar rsync find cpio dd

thanks

PS. If you come across this post late, be it a week or even a month late,
please do comment, I hope this thread can be a one stop place for people
looking for concerns over cloning root partitions.


--
Tong (remove underscore(s) to reply)
http://xpt.sourceforge.net/

--
Posted via a free Usenet account from http://www.teranews.com

* Tong * wrote:

> Hi,
>
> I'm trying to compile a comprehensive document on cloning root partitions.
> My immediate goal is to clone my current working Linux to external USB HD,
> so that I can use it wherever I go.
>
> By comprehensive I mean it should not be as simple minded as
>
> dd if=/dev/hda2 of=/dev/sda2
>
> or
>
> cp -a / /mnt/point
>
> or
>
> tar -p -m cf - / | (cd /mnt/point; tar xf - )
>
> I know they work, but there are so many things have been left out. By
> comprehensive, I mean I want to know all relevant things that need to be
> considered.
>
> For example for dd, let alone its rigid limitation, if you use it, at
> least the 'conv=sync,noerror bs=4k' options should be used: sync,noerror
> just means continue and zero fill any error blocks, bs=4k just writes 4k
> at a time which will speed things up a lot. For cp, at least 'cp -ax'
> should be used.
>
> But there are still much more to it.
>
> First, directories that don't need to copy over, like /tmp, /proc. With
> modern Linux that uses udev, the /dev and /sys don't need to be copied
> either. Anything else (besides distro specifics like
> /var/cache/apt/archives)?
>
> 2nd, the clone partition should be made bootable, by grub or lilo.
>
> Anything else? Like the concerns of /etc/fstab...
>
> Last, with all the above concerns, how to achieve them with various tools?
>
> Keywords: tar rsync find cpio dd
>
> thanks

I'm not an expert in this area,
but I would have thought it was advisable
not to clone / while it is mounted;
I would run knoppix, or something like that, and then copy with "cp -a".

--
Timothy Murphy
e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland