Quoting Donald Tripp <[log in to unmask]>:

> When you do any upgrade its always important to make a backup of  
> critical system files along with the user space. If you have any  
> special daemons running make sure to backup the config files for  
> those as well. From 4 to 4 there were some base level changes, so  
> you may have to do a bit of tweaking, but probably not much. When  
> you reboot make sure the grub config loads the newest kernel, so the  
> highest number. I'm assuming your probably running ext3, so you  
> should be fine.
>
> When you think of "upgrading" a linux system, don't think of it in  
> terms of a windows desktop like upgrade, but more like a bunch of  
> updates put together. Yes, there were some significant changes in  
> RHEL/SL 5, but not really any earth-shatering stuff. If you ever  
> look at the iso files once they are mounted, all you will see is a  
> bunch of RPM files. The "upgrade" will install these RPM files, and  
> any necessary dependencies. Many of them will simply be newer  
> versions of files you already have. If there are new files, or some  
> older files that will no longer be used, your system will just take  
> more hard drive space then a clean install would. If an RPM creates  
> a new configuration file, the original should still be there as well.
>
> Off the top of my head I can't think of any system specific  
> applications that had major configuration file changes between SL 4  
> and 5. The way your network interfaces are handled will change in  
> 5.4, so if you made any changes to the ifcfg-eth files you will may  
> have to modify the corresponding network service files.
>
> Good luck!
>
>
> On Dec 8, 2009, at 10:05 PM, g wrote:
>
>> [log in to unmask] wrote:
>>> I am running Scientific Linux 4.3 and I want to upgrade to the latest
>>> version 5.4. Now, I have downloaded the two .iso files. If I install these,
>>> will I be able to keep my existing file system, or will the volume in my
>>> hard drive be erased, and hence I will have to save my programs and files
>>> somewhere else.
>>
>> if you select *upgrade*, it _should_ be go well.
>>
>> have a look at;
>>  https://www.scientificlinux.org/documentation/howto/upgrade.5x
>>
>>> In addition, what else can go wrong when doing this? (I will not have a
>>> problem with insufficient disk space.
>>
>> nothing that i am aware of. in fact, other than time frame, for me,  
>> it was as
>> simple and smooth as doing a yum update.
>>
>>
>> while i am at it, my thanks to scientific linux team for all their work in
>> making upgrade so easy and trouble free.
>>
>> i would have said so sooner, but i have been busy rebuilding 2  
>> fedora systems
>> and '/home' in this box and one other, when i ran an update, and tried to
>> upgrade them from f11 to f12.
>>
>> system got trash in that it clobbered superblock on 3 hard drives along with
>> trashing hard drives to force me to rebuild system from blocks of  
>> what i found
>> in fsck.ext3 in recover mode.
>>
>> i did have backups that made '/home' recover easier, but there where several
>> bad backup dvd's that checked good when they were made.
>>
>>
>> to that end, be sure that you back your system and '/home' and  
>> verify backups
>> before you do any upgrade. regardless of what distrib it is.
>>
>> hth.
>>
>> later.
>>
>> --
>>
>> peace out.
>>
>> tc,hago.
>>
>> g
>> .
>>
>> ****
>> in a free world without fences, who needs gates.
>> **
>> help microsoft stamp out piracy - give linux to a friend today.
>> **
>> to mess up a linux box, you need to work at it.
>> to mess up an ms windows box, you just need to *look* at it.
>> **
>> learn linux:
>> 'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html
>> 'The Linux Documentation Project' http://www.tldp.org/
>> 'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html
>> 'HowtoForge' http://howtoforge.com/
>> ****
>>
>

Thank you all for that helpful information. However, I have run into  
another problem. I have mounted the first .iso file but I can not find  
where the installation file--is it .sh or .exe?--is. Does anybody know  
what file to look for in order to get this started, or point me to the  
documentation where I can find this information?

Thank You for Responding:

Andrew Stallard