[CentOS-devel] Status of CentOS 5 for the i586?

Sun Jun 5 20:37:46 UTC 2011
Cody Jackson <supertanker13 at gmail.com>

On 6/5/11, Dmitry E. Mikhailov <d.mikhailov at infocommunications.ru> wrote:

> A year ago I read instructions on centos.org. About ten original Pentium boxes
> were converted from CentOS 4.* and are used for small businesses as an
> el-cheapo router/fileserver/etc

Bravo for not throwing out usable old hardware! (Sorry, just had to go
there--I collect old computers like candy. Except I don't eat them.
But I digress. Moving on!)

> And there is a
> half-dead repo at my server http://infocs.ru/rpmrepo/

I notice mesa is in there--according to the wiki page, the mesa
package contains cmov instructions, so it'll have to be rebuilt too.
I'll play around with that later today in mock and see what happens.

> 0)pull HDD from old box
> 1)put that harddrive to modern box
> 2)install OS to it
> 3)boot it (on modern box)
> 4)copy and install an i586 kernel
> 5)remove i686 kernel
> 6)downgrade glibc* and openssl from i686 to i386 version
> 7)put that HDD to old box and be happy.

Yep! That's exactly what I've been doing. I set up a lightweight
"base" system kickstart that I can use over PXE to quickly install a
thin system (while the hard drive is in the i686 system) in about five
minutes. Then I install the kernel, downgrade packages, and slap it in
the test box. It takes about 20 minutes to set up, maybe 30 if I'm
having a bad day. I'll probably need to trim the kickstart down a
little more, but it works like a charm.

Building the i586 kernel is probably the most time consuming bit of
the whole process, but once you get it to build once you don't need to
do it again, baring security updates. Even then, it seems it's a
fairly simple process.

> It's hard to use yum also because it needs 64+ MB of RAM just to start doing
> something.

Yep--yum loooooves to eat memory like popcorn at the theatre. I'll
keep a closer eye on memory usage next time--hard to tell what's
swapping and what's reading the RPM database or doing things with

> Can't imagine to use i586 boxes as a desktop with GUI. Thin client maybe,
> but
> there are better distros for that. The memory is the primary limitation. But
> a router with PPTP server and a Samba can work pretty well at
> Pentium-200/32MB/6.4GB.

Memory is a problem, definitely. My test machine has 76MB of free RAM.
(If I were unlazy enough to put in a discrete video card, that would
go up to 80MB). It will run X. It will run XFCE with a lot of
swapping. Forget Firefox. ;) The laptop might perform better--it has a
whopping 192MB (!) of RAM for an AMD K6 400Mhz. IIRC, it's running
Debian with XFCE right now, so it's usable.

> P.S. For happy owners for IBM/Cyrix CPUs. They carry the necessary
> instructions for an i686 kernel to boot successfully AFAIR. I was surprised.
> It's a pity they run too hot to be reasonably used.

Really? That's interesting. I have an IBM 6x86 (PR 150) I can plug
into my test box. I'll have to play around with that. I'm also going
to see, just for giggles, if I can scrounge up another Super-7
motherboard or two to expand the testing equipment museum. I have a
lot more CPUs than motherboards.

On 6/5/11, Karanbir Singh <mail-lists at karan.org> wrote:
> [snip]
> The hard part is
> just identifying where the resources are being used and what is the
> minimum we want to deliver for. I don't think 128 or even 256M of ram is
> an unreasonable minimum. Atleast for step-1.

I don't know what "modern" i586 systems have (VIA, etc), but I do know
that a lot of the old systems have trouble breaching the 64MB barrier.
My test box came with 16MB of RAM; by some miracle, I had a few SIMMs
in the big tub of parts under the bed (memory from my *486sx* I think)
and I bumped it up to 80MB total. As Dmitry mentioned, it's great for
a filesever/router. Even a simple static web server if you wanted to
go there--but don't use Apache, use something like Lighttpd instead.

Iirc, the memory minimum for the text-mode installer is 64MB. I think
that's a sane requirement, although if it could go lower, I see no
reason why not to bump it down...if people are crazy enough (like me)
to try this on machines with <64MB of RAM, let them find out what
happens. It'll be educational for them!

Cody Jackson