Re: clone a linux system over the network

["Lee Whatley, Contractor" <lwhatley ctr navo hpc mil>]

wolf2k5 wrote:
> Hi,
>
> I need to migrate a Linux system from a server to another one.
>
> I cannot reinstall the OS and applications on the new server and then
> migrate the data from the old server, since that would require too
> much time.
>
> In the past, to migrate a Linux system from a server to a new one with
> HD of the same size, I shut down the servers, booted a Linux live CD
> (Knoppix) on them and used 'dd' and 'netcat' to clone the system over
> the network: that worked fine, but with two cons:
>
> - It is pretty slow, since it will copy over even blank data.
>
> - You cannot resize the partitions: if the new server has a bigger
> disk, you cannot enlarge the original partition to use the additional
> space.
>
> Do you know any better way to clone the system over the network that
> will fix the above problems?
>  
> I think the commercial application Symantec Ghost can do it, but I am
> looking for something free.
>
> It would be great if such tool supported PXE boot too.
>
> On a separate note, do you know how to boot Knoppix via PXE without
> using the Knoppix Terminal Server (that requires an additional
> machine)?
> I already have a Linux host running TFTP/DHCP/NFS servers and use it
> to perform Red Hat Enterprise Linux installations via PXE.
> How do I configure it to perform Knoppix boots via PXE?

Well here's a pretty quick and dirty way to do it:
1.)Run a "dump" on each filesystem on your old machine
2.)Share the dumps on your nfs server
3.)Boot the new server from Redhat install CD.  Partition and format the 
disks using anaconda and then escape to a shell (I think it's VT 2 or 3)
4.)Set up the network on the new machine (just use ifconfig and route) 
and then nfs-mount the dump files
5.)Restore the dump files to your newly created filesystems
6.)Manually install grub to the MBR
7.)Reboot