What if I wanted to change the processor?

jpl888

Ok here is the scenario.

I am using Gentoo as server OS for all my SME customers, one of the advantages of Gentoo being that you never have to do a major upgrade and I have Gentoo compiled for say a Pentium IV at each site.

Thinking ahead I will want to change the server hardware at some point in the future i.e. when it dies or is no longer capable of coping with the demands of modern computing. Intel will no doubt have realeased the latest Pentium VIII ninja b~@~ard processor and I don't want to do a complete reinstall to recompile the system for the new processor arch.

I do not want to use a "generic" optimisation as it just doesn't seem elegant, I want to know that my customers server is running as fast as its little legs will carry it.

My question then is this. How do I recompile the existing system for the new processor arch?

Voltago · Posted: Wed Apr 13, 2005 1:53 pm Post subject:

1. Edit /etc/make.conf
2. Type

jpl888 · Posted: Wed Apr 13, 2005 2:04 pm Post subject:

Wow thanks for such a prompt reply Voltago! and of course the answer.

Would I do that before or after I have imaged/moved the old hard disk into the new server?

Of course I realise I would have to recompile the kernel to support the new hardware.

drwook · Veteran Joined: 30 Mar 2005 Posts: 1324 Location: London

I'd do it on the new hardware, the compile time should be far less on a faster processor, everything else being equal. Maybe more 'the Ilyad' than War & Peace

But if you couldn't for whatever reason I guess you could probably recompile on anything in a chroot'd environment...

jpl888 · Posted: Wed Apr 13, 2005 2:51 pm Post subject:

So what ur saying is if I had a problem starting up the old hard-disk/partitions on the new server I could just boot from the livecd, chroot into the old environment and run "emerge -e world" from there, great simplicity itself thankyou drwook.

I will have to try it sometime when I get chance although I am a bit simple so the Ilyad or War and Peace is beyond me maybe a car magazine with de nice pictures vrm vrmmmm :wink:

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

The important thing is to not do insane optimisations on a server. Your CFLAGS should be three or four flags long at most.

jpl888 · Posted: Wed Apr 13, 2005 9:32 pm Post subject:

I would be too afraid to do more than 3 (and I'm not even sure about that)

Voltago · Posted: Wed Apr 13, 2005 9:36 pm Post subject:

jpl888 · Posted: Wed Apr 13, 2005 9:41 pm Post subject:

I knew there would be something like that involved which is why I hoped somebody already knew. Maybe I will just have to try some stuff myself. It would be interesting to see what happens wouldn't it?