On December 23, 2005 I "upgraded" umfs01.grid.umich.edu from the i686 (32 bit) version of Scientific Linux 4.1 to the x86_64 (64 bit) version of Scientific Linux 4.2. Since an upgrade between 32 bit and 64 bit is not supported, this meant I needed to do a new installation. Fortunately we have a script (originating with Eric Myers) call 'Tara' which creates a set of two tarballs containing a "generic" and "system-specific" set of configuration files from the system on which you run it.

I ran Tara before upgrading umfs01. It is located in our /usr/local/adm (softlink to /afs/atlas.umich.edu/i386_linux24/usr/local/adm). First "klog" as admin on AFS so you can write there. Then run 'Tara' to create a single tar.gz file containing the generic and specific config files. I saved the output of the following commands to files as well:

• ifconfig > ifconfig_umfs01.log
• df > ifconfig_umfs01.log

Next step is to save the following directories:

• tar -zcvf umfs01_root.tar.gz /root
• tar -zcvf umfs01_usr_src.tar.gz /usr/src
• tar -zcvf umfs01_home.tar.gz /home

Once I saved the system details I boot from the x86_64 version of Scientic Linux 4.2 (CD 1) and do a "custom" install. I make sure not to touch any of the /dataxx partitions which may exist. I let the install format the /, /boot, /lib, /var and /usr areas if they already exist. You want to make sure to use the same partitions so the Tara saved configs are still applicable. I choose to have any packages related to system management or compilation installed in addition to the defaults (also get the "editors").

When the install finishes I reboot into the new installation and run Tara again. This time I have the config files from the installation in case restoring the old ones breaks anything. Once they are saved I just unpack the original configs into the new system:

• cd /
• tar -zxvf /umfs01_generic.tar.gz
• tar -zxvf /umfs01_specific.tar.gz

I then reboot to see what breaks. Last step is to restore the /root and /usr/src/ (if needed).

-- ShawnMcKee - 31 Dec 2005