[CentOS] SCSI install to IDE install - help

Wed Apr 26 17:39:30 UTC 2006
Lamar Owen <lowen at pari.edu>

On Monday 24 April 2006 17:43, Phil Schaffner wrote:
> Can  do it with tar (or cpio or cp -aux).

The OP asked about image copying.  In a full image copy, with the assumption 
that the source disk is removed prior to the reboot with the new disk, one 
doesn't have to worry about label dupes and such.

I've found a dd of the whole disk to an identical disk works very well, with 

> > and rebooted.  Came right up. Note that the rescue CD does need to be the
> > same major kernel version as the system.

> and have appropriate version of mkinitrd.

Yes, this is very true.

> The above apparently assumes you are using the same labels on the source
> and destination disks.  If so, you must remove the original disk before
> attempting a reboot or problems with duplicate labels will ensue.

Removal of the source was assumed; sorry I didn't make that explicit.  It 
vastly simplifies things if you do an image copy and remove the source drive 
before proceeding.

> > I did this once going the other way, from an IDE disk to a SCSI disk. It
> > worked fine, but was a little tedious.

> Have done it both ways, and with/without LVM.  Always a bit tedious but
> workable.  Major problems (except for potential errors editing fstab and
> grub.conf) tend to be with initrd and grub/BIOS device ordering.

Your instructions were complete, and have great information.  And for cases 
where you might want to go to a different sized drive or use different 
filesystem sizes this is a good way to go; I use Paragon Partition Manager 
for many tasks, but resizing SELinux labeled ext3 filesystems is not one of 
them.  For a straight clone and for NTFS and FAT Paragon works great (and the 
rescue CD version is a bootable Linux CD with the Partition Manager GUI app 
running on a 2.4.x kernel).

But it is quite a bit simpler to image the disk (either with imaging hardware 
or software, although a SCSI-> IDE clone would likely be software-only) and 
remove the source, once the proper edits have been made using the rescue 
disk. GNU parted and its frontends can do this as well.
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772