Compiling 4-RELEASE on 5-STABLE

[Subhro]

On Thu, 14 Oct 2004 01:18:25 -0400 (EDT), John Gillis <zefram at zefram.net> wrote:
>however.. there are still things that could go wrong and I
> prefer not to find out when a production server heads south or doesn't
> have the right firmware on the RAID card.. so that's why I lag.

You can very well lag but doing so you would be creating apain in your
forehead. Because everything that worked on 4.X-Release ( repeat,
notice the word release) will also work on 5.Y-Release ( notice the
word release). And also I would argue against keeping your boxes in
the 4.X tree because as new releases are made available, the source
codes of the ports are also changed to make it portable to the new
tree. Most of the times tyhey DO compile on the old tree but you would
be loosing features and performance. For example, there is a huge
difference in performance when Xorg is compiled on gcc 2.95 and on gcc
3.4.2. If you are interested then contact me off the list. I would be
happy to send you the performance monitor logs.

>        Also, at least one piece of hardware is near impossible to
> upgrade. An old 486/25 that's running Snort, without a cd-rom and a 200M
> hard drive.

Negative, this hardware is also upgradable. Just the catch is it is
not SELF upgradable. I mean you can expect to compile the tree on the
486 itself. But you can very well compile its tree and kernel on a
Pentium (say) and install it on the 200M harddisk. I have quite a few
routers which have a lot similar configuration to yours and they work
till date without complaining. Just the upgradng is a bit troublesome
compared to the newer systems. Refer to the CFLAGS parameter in man
make.conf

>        What about my question about boot strapping? Does that ensure that
> I could compile the world/kernel of 4.x on 5.3?
>                John
No it does not. To be precise as far as I know, there is no way you
can compile a native 4.X binary of any kind (application, kernel,
bootstrap, you name it) on a 5.X box. Although you CAN run native 4.X
binaries on a 5.X kernel using the compatibility layers. Refer to
/usr/src/sys/NOTES for further information about compiling the
compatibility layers. And yes the boot strap code has also changed
from 4.X. Refer to /usr/src/UPDATING for a brief log about what had
been changed since the 4.X tree. Also you can find detailed
information about upgrading a 4.X tree to a 5.Y tree (although not
recommended for other performance, security and a number of other
reasons).

Regards
S.

-- 
Subhro Sankha Kar
School of Information Technology
Block AQ-13/1 Sector V
ZIP 700091
India