[CentOS] i386 or x86_64 installation

Johnny Hughes mailing-lists at hughesjr.com
Mon Jan 22 12:28:34 UTC 2007


On Sun, 2007-01-21 at 16:56 -0500, Ted Miller wrote:
> While commenting on the subject of:
> "Re: [CentOS] Risks of installing i386 rpms on a x86_64 CentOS 4.4 
> installation"
> Johnny Hughes wrote:
> 
> [snip]
> 
> > Personally, I would only install the x86_64 distro if I was reasonably
> > sure that I would not require i386 RPMS (or minimal i386 RPMS).
> > 
> > I just use i386 on all workstations and I use x86_64 on servers ... and
> > even on servers, only ones that will really be under heavy load or will
> > definitely not need i386 packages.
> 
> If you wouldn't mind Johnny, could you elaborate on your "Personally..." 
> recommendation?  I am running 4.4 x86_64 on AMD hardware (x64 3500+, 1G, 
> 3x160G SATA, Gigabyte nvidia nForce-4 Ultra chipset MB w/ Gigabyte 6200 
> series pci-e graphics) for a "personal workstation" (otherwise known as a 
> heavily used home computer).  I just counted in yumex and I have about 77 
> packages with both 64 and 32 bit versions installed.  One (of several) 
> reason I switched to Centos from Mandriva is the poor support Mandriva had 
> for 64 bit versions.  Most packages in their repos were only available in 
> 32 bit versions, and some minor OS upgrades came out only in 32bit.  Centos 
> seems to be very even-handed about the architectures (at least i836 vs. 
> x86_64).

It is a headache (IMHO) to have to maintain a bunch of multiple arch
RPMS.  As I said before, IF you stay with only the 32bit items that are
in the official x86_64 repository then you should be mostly fine.

I personally think that the way x86_64 is handled is a buggy kludge
(yes, I know I am the maintainer of this $ARCH :P).  An example is that
if you install an i386 and x86_64 package of the same name ... then
remove the i386 package ... some of the shared files (that were
identical on install and worked ok) that are in both might be removed.
These should stay as the x86_64 package is still installed.

This happens often enough that I wrote a script that figures out what
should be there on x86_64 packages and gives me a list of packages that
I need to reinstall to get the shared files back if they are missing.

If you install the packages and keep them there, this is not a problem.

I personally think that there should not be any i386 bits in the x86_64
repo and that all items should be x86_64 only ... or that they need to
better engineer a solution to handle docs / shared files (for both
installation and removal).

> So far the 64/32 bit issue has only come up a couple of times, and I was 
> able to resolve it leaving any blood (from my head) on the wall.  Should I 
> be looking at switching to 32 bit?  If so, how on earth does one do that 
> without rebuilding the machine from scratch?  I still don't have this one 
> tweaked very well, and don't have all the programs I want installed.  I'd 
> rather not start over AGAIN.

If you can live with the selection of RPMS in the x86_64 distro, then
you should be OK.

If you are going to compile items that you expect to work on other
x86_64 machines that are 64bit, then you will need a separate chroot
that does not contain so many i386 libraries (or even use mock to build
with) to build x86_64 packages ... and a chroot for i386 too if
appropriate (ie, you want to build 32bit apps to run on the i386
distro).

(What will happen is that unless you are very careful, you will add
64bit libs to 32bit complied programs and also 32bit libs to 64bit
compiled programs)

> If it helps, my use is the usual email, web surfing, OpenOffice, plus 
> desktop publishing (scribus), graphics (gimp, cinepaint, and others), and 
> audio editing (audacity, etc) and I am trying to learn C++ (eclipse based). 
>   I run VMWare server for those programs which I am forced to use in other 
> operating systems (and also to isolate ipcop).  I am not a newbie, but 
> neither am I an experienced old hand.  I have been using Linux for my 
> personal computing for about a year (since I got this hardware).  I have 
> had a Linux file server in my basement for about four years, but I set it 
> up once and mostly ignored it (I think it runs RH8).
> 

My personal opinion is that the benefits of x86_64 are marginal for
normal workstation use (however I see you use cinepaint ... video
processing can sometimes need the added x86_64 features).

If you need to bring in many i386 apps into x86_64, especially if you
need to bring in many "non CentOS x86_64 repo" type i386 RPMS, then I
would think that (at least for CentOS-4) and i386 distro would be
better.

CentOS-5 beta will have an OOo version for x86_64 (at least the beta
from upstream does), so that is one major obstacle overcome. 

> Your personal comments on my situation are welcome, as well as anyone else 
> who wants to chime in.
> 

If you are currently able to maintain your system and are happy with it,
then keep it as is ... just understand what causes the problems and how
to work around them. (using --nodocs or --force ... be very careful with
--force though).  Also the potential compile problems that can be
introduced, etc.

Thanks,
Johnny Hughes
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.centos.org/pipermail/centos/attachments/20070122/32eca47f/attachment.sig>


More information about the CentOS mailing list