RHEL5 32-to-64 upgrade?

[Peter Skensved]

> 
> Is there an upgrade path from 32 to 64 bit other than a complete
> reinstall of the OS?
> Thanks,
> John Dalbec
>

  I tried it with CentOS 5.5 once . It failed miserably - the installer
gets very confused about what packages are installed. Your best bet is
probably to do a reinstall. You don't necessarily have to do a full
wipe of your disk but it depends a bit on your layout and policies.

 If you only install from RPM files and always install your own binaries
in /usr/local or /opt life is easy. Save a list of what is installed :
rpm -qa --qf "%{NAME}\n" | sort | uniq > list_of_32_bit_rpm_files

 Do a new 64 bit install and run the above command again :
rpm -qa --qf "%{NAME}\n" | sort | uniq > list_of_64_bit_rpm_files

 With a few diff, grep and cut commands you can now make lists of files
for yum to add and remove ( the uniq command above takes care of the
duplicate 64 and 32 bit names )

 Do recursive diffs on /etc and a copy of your old /etc to see what 
needs tinkering with. In most cases there are no changes needed for
a switch to 64 bits. 

 If you're brave just boot the 64 bit installer disk, stop at the disk
partitioning screen, get a shell, wipe everything except lost+found
and your own stuff ( like /home and /usr/local ) and rename /var and /etc.
Then go back to the installer, select "do not format" and proceed with the
install. That saves you the restore step. 

                                               peter
----

Peter Skensved                          Email : peter at SNO.Phy.QueensU.CA
Dept. of Physics,
Queen's University,
Kingston, Ontario,
Canada