On Thu, 16 Jun 2011, Yasha Karant wrote:

> From the reply below:
>
>  I figure it's possible to choose "advanced" partitioning and simply
> uncheck "format" for all existing partitions while choosing the old
> mountpoints. Technically, that's an unsupported upgrade, while you don't
> have to boot with an "upgradeany" kernel parameter or choose "update
> existing linux installation" in the anaconda GUI. And I figure it's what
> happened here.
>
> End quote.
>
> That is correct.  It also is correct that RHEL and any faithful clones
> (such as CentOS and SL) does not allow a major release upgrade, only a
> minor release.  Assuming one has a decent data rate network connection,
> up to and including RHEL 5.6 (in my case, via CentOS 5.6) minor upgrades
> (e.g., RHEL 5.5 to RHEL 5.6) could be done by internal update mechanism
> without requiring a DVD (installation media) or a reformatting of any
> partition (unless, of course, the size of the partition was too small --
> almost unheard of with the current price of a 1 TByte SATA drive).
>
> For a major release, one must use the media or other specialized means
> and requires a full upgrade.  However, when I went from RHEL 4 to RHEL 5
> (via CentOS), I did not have to reformat and the installation was
> successful -- overwriting files that had the same function but newer
> versions.
>
> This is not working with SL6 from Centos 5 (RHEL 6 from RHEL 5) and
> presumably will not work with CentOS 6 when it is available nor with
> RHEL 6 were we to license the media for fee.

Yes that is correct.  As noted before the "upgradeany" installer option is 
available but it will NOT work as hoped.

>
> It would be useful if this were made clear -- if it is stated that these
> entities:  / ,  /var , /usr must be reformatted, I apologize for missing
> this statement in the release notes.
>
> At this point, I must copy a whole number of directories to
> partitions/drives that do not need to be reformatted (e.g.,  /usr/local,
> /opt , /home that I keep in separate ext2 partitions) to preserve a
> number of utilities that I will then cp -pr (or tar) back to whatever SL
> 6 does.
>
> Before I begin, are there any things other than these (/, /var, /usr)
> that must be reformatted?

/boot if you use that.  System partitions is what is needed to be 
reformatted.

>
> Yasha Karant
>
> On 06/16/2011 11:51 AM, Stephan Wiesand wrote:
>> On Jun 16, 2011, at 20:39 , Connie Sieh wrote:
>>
>>> On Thu, 16 Jun 2011, Urs Beyerle wrote:
>>>
>>>> On 06/16/2011 06:58 PM, Yasha Karant wrote:
>>>>> This one is from a SL6 install. SL and CentOS are both RHEL.  I keep the system utilities stock (the same as TUV, RHEL in this case), except for the use of
>>>>> the graphics card driver from the graphics card vendor, not generic X (e.g., on this machine, the Nvidia driver for linux X).
>>>>> I am switching to SL over CentOS because (1) we do not have funding luxury to license the binaries from RH and (2) CentOS 6 is not yet available despite RHEL
>>>>> 6.1 already having been released.  Other than re-branding, SL and CentOS both claim to be RHEL clones -- I know that the RPMs that work on RHEL release X work
>>>>> just as well on both CentOS and SL of the same release.
>>>>>
>>>>> (Why not SL over CentOS?  A matter of history, not a specific choice. With the upcoming demise of Fermilab as a direct experimental facility, hopefully the EU
>>>>> will continue to fund CERN and not be shortsighted as USA neoliberal Republican Tea Partists force upon the USA, and thus maintain support for SL.)
>>>>>
>>>>> I did not reformat / , /var, /usr .  Must these be reformatted?
>>>>
>>>> Yes, otherwise you will have a mixture of the old system (CentOS5?) and the new SL6 system on /, /var, /usr. This will definitely not work.
>>>>
>>>> If you want to keep old data you have to do an update instead of an install. But I don't know if CentOS5 can be update to SL60 with SL60 install DVD. My guess
>>>> is that this will not work.
>>>
>>> An update from "5" to "6" is NOT supported by either RedHat or SL.  RedHat has code to specifically not allow it.
>>> Others have tried to "force" an upgrade and were not successful.
>>
>> I figure it's possible to choose "advanced" partitioning and simply uncheck "format" for all existing partitions while choosing the old mountpoints. Technically, that's an unsupported upgrade, while you don't have to boot with an "upgradeany" kernel parameter or choose "update existing linux installation" in the anaconda GUI. And I figure it's what happened here.
>>
>> - Stephan
>>
>>>
>>>>
>>>> To be save make a backup before you format the partitions.
>>>>
>>>>
>>>>> Will X86-64 SL6 allow me to keep these as ext2 (no journal)?
>>>>
>>>> I think if you choose custom partitioning you can format your partitions with ext2. Just curious, what's the reason to use "old" ext2?
>>>>
>>>> Cheers,
>>>>
>>>>     Urs
>>>>
>>>>>
>>>>
>>>
>>> -Connie Sieh
>>
>

-Connie Sieh