Gentoo /etc/._cfg*

[I.M.O.G.]

So I'm setting up Gentoo on a T400 Thinkpad for the first time. EDIT: I ended up babbling a bit, my question is at the bottom if you want to skip to that.

I'm doing so thru the Ubuntu 8.10 livecd, because I've heard things don't go well with the Gentoo CD due to the T400's CD drive interface. I followed the alternate install guide to get going, I'm chroot'ed, and things are going well - its pretty neat being on a livecd, setting up another OS from it, while using openoffice to write a paper for school in the meantime. When I'm done, I'll have Gentoo dual-booting with Windows XP.

The T400 has a core 2 duo and I read that gcc-4.3.2 lets you use march=core2 for further optimization, rather than march=prescott which is the recommended safe setting with gcc-4.1.2 that comes with the latest stage3 tarball. So I've upgraded to gcc-4.3.2 alright, and cleaned out the old gcc.

I really should be working on this paper for school, so rather than doing the revdep-rebuild route after upgrading gcc, I opted for emerge -e system - I have some time, and I was curious how this new core2duo @2.53Ghz compiles compared to the Pentium [email protected] I had gentoo on previously. LOTS faster.

So anyways, my question. After doing an emerge -e system I'm left with a slew of /etc/._cfg* files which need updated (about 28). How do other Gentoo users handle these files? A lot of them I don't know what they are. Occasionally there is one I know I have manually modified, so I'll compare the new to the old manually by using nano to look at the files and then make the appropriate changes in the new version of the file and overwrite the old version. But most of the files I have never seen before and/or I don't understand what they do and I've never made changes to them, I think - should I overwrite all the old versions of these with the new versions? This is a cumbersome part of Gentoo I remember from the last time I had it installed, so I ask because I'm probably doing something wrong or theres a better way to handle these files.

Thanks for any input or guidance.

 

[{PMS}fishy]

So anyways, my question. After doing an emerge -e system I'm left with a slew of /etc/._cfg* files which need updated (about 28). How do other Gentoo users handle these files? A lot of them I don't know what they are. Occasionally there is one I know I have manually modified, so I'll compare the new to the old manually by using nano to look at the files and then make the appropriate changes in the new version of the file and overwrite the old version. But most of the files I have never seen before and/or I don't understand what they do and I've never made changes to them, I think - should I overwrite all the old versions of these with the new versions? This is a cumbersome part of Gentoo I remember from the last time I had it installed, so I ask because I'm probably doing something wrong or theres a better way to handle these files.

Thanks for any input or guidance.

sudo etc-update

All trivial changes will be merged for you.

Most things can be accepted, but if you made any changes to config files such as Apache, be careful because you can overwrite them by mistake.

Here is the guide -- > http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=3&chap=4

 

[I.M.O.G.]

Fishy, thank you. I'll give that a shot, sounds exactly like what I was looking for. dispatch-conf looks like it does something similar but is referred to as safer since it allows reversion to previous config files.. I assume you suggest etc-update because your assuming I won't make any mistakes.

I'm not sure thats a good assumption to make! haha

Thanks again.

 

[{PMS}fishy]

Fishy, thank you. I'll give that a shot, sounds exactly like what I was looking for. dispatch-conf looks like it does something similar but is referred to as safer since it allows reversion to previous config files.. I assume you suggest etc-update because your assuming I won't make any mistakes.

I'm not sure thats a good assumption to make! haha

Thanks again.

Just don't auto merge all changes. You'll be ok.

 

[MRD]

The T400 has a core 2 duo and I read that gcc-4.3.2 lets you use march=core2 for further optimization, rather than march=prescott which is the recommended safe setting with gcc-4.1.2 that comes with the latest stage3 tarball. So I've upgraded to gcc-4.3.2 alright, and cleaned out the old gcc.

Actually, I believe the setting you want to use is -march=nocona. I'm not 100% sure of that as I'm an AMD guy, but I believe that Prescott is for P4's only (and maybe Pentium D's?).

As for your config question, look at the list. If you have never changed any of them, then just use -5 and overwrite them all with updates. If you've changed them, manually merge the changes or decide how to upgrade them. If they are the stock files that came with the previous version, they can just be upgraded automatically in most cases.

You can get into big trouble if you overwrite things like xorg.conf. (Not really big trouble... it's pretty easily fixable if you are decently Linux savvy, but the first time I automerged everything, I couldn't fix X... but Iwas pretty noob then.)

 

[{PMS}fishy]

Actually, I believe the setting you want to use is -march=nocona. I'm not 100% sure of that as I'm an AMD guy, but I believe that Prescott is for P4's only (and maybe Pentium D's?).

As for your config question, look at the list. If you have never changed any of them, then just use -5 and overwrite them all with updates. If you've changed them, manually merge the changes or decide how to upgrade them. If they are the stock files that came with the previous version, they can just be upgraded automatically in most cases.

You can get into big trouble if you overwrite things like xorg.conf. (Not really big trouble... it's pretty easily fixable if you are decently Linux savvy, but the first time I automerged everything, I couldn't fix X... but Iwas pretty noob then.)

core2 is correct.

Tuning for Intel Core 2 processors is available via -mtune=core2 and -march=core2.

http://gcc.gnu.org/gcc-4.3/changes.html

 

[MRD]

I meant in the older gcc's... as opposed to prescott.

I actually went with gcc 4.3.2 myself, as it has support for amdfam10 (phenom) with sse4a, abm, etc.

 

[petteyg359]

-mtune should not be used unless there is no -march available for your CPU, AFAIK.

 

[Rinne]

Yep, it was nocona for older GCC versions and Core2...

since GCC 4.2 you can also use "native" which will figure the optimal architecture out by itself, I'm using "core2" myself as well... don't trust those auto recon systems

Be aware though, that GCC 4.3 has made some major changes to the compiler requirements towards programmes...

That is that you have to add all includes by yourself now, before the compiler could add them automatically... It has generally been recommended to add them yourself, but some developers didn't and thus some programmes won't compile anymore.. I didn't compile a lot (like 2-3 programmes so far) with GCC 4.3, but already ran into one programme that wouldn't compile and had to "patch" it myself for now. That was none of the programmes available via portage, though..

 

[Captain Newbie]

Just don't auto merge all changes. You'll be ok.

Seriously

I myself use dispatch-conf, but to each their own.

 

[MRD]

I've been using GCC 4.3.2 and had no problems at all (amd64). I wanted the -march=amdfam10 option for my phenom.