Pario TechnoBlob » Gentoo

Debian Linux in – Gentoo Linux out

Hans-Henry Jakobsen — Sun, 20 Jan 2008 00:41:58 +0000

As I write this post my last Gentoo Linux server is about to be converted to be a Debian Etch server. This is a sad decision I’ve made since I’ve used Gentoo Linux running web, mail and databases since version 1.0RC1 december 2000 both in stable and unstable versions. This is a result of less time to ponder in front of my computer so the decision to use Debian was a easy decision since it is a “friendlier” system to keep running. I’ve learned a lot in these years and would really recommend Gentoo Linux to all users interested in learning linux.

A positive result of this change of Linux distribution is that I’m now successfully running Zimbra Collaboration Suite 5.0 Open Source Edition on my Debian server and it’s working great. I might make a post about how I did it and migrated from my Postfix/Dovecot (w/maildir) installation.

Configure lm_sensors in Gentoo

Hans-Henry Jakobsen — Fri, 10 Aug 2007 22:48:50 +0000

Use the script sensors-configure to configure the lm_sensors program.
It’s a part of the sys-apps/lm_sensors suite.

Profiles in Gentoo

Hans-Henry Jakobsen — Sun, 05 Aug 2007 18:16:38 +0000

Supported profiles
You can view the list of profiles on your architecture officially supported by Gentoo developers when you emerge eselect and then run the following command:

Viewing supported profiles

eselect profile list

Profile updating instructions

Important:
Make sure your Portage is updated before performing any profile changes.

First, run emerge eselect. The eselect utility will let you view and select profiles easily, without needing to create or remove symlinks by hand.

Profile selection with eselect
(View available profiles)

# eselect profile list

(Select the number of your desired profile from the list)

# eselect profile set

If you’d still prefer to change profiles manually, then simply do the following:

Changing profiles manually

# rm /etc/make.profile
# ln -s ../usr/portage/profiles/ /etc/make.profile

Emerge new system from old World file

Hans-Henry Jakobsen — Thu, 26 Jul 2007 22:36:19 +0000

A slick script or method to compile the apps listed in the world file, from an existing system to the new system, all together at once, rather that typing in all of those application names into one giant emerge command.

emerge -av $(cat /path/to/oldworld)

Estimate emerge time

Hans-Henry Jakobsen — Wed, 25 Jul 2007 20:31:34 +0000

You can analyze your system’s emerge.log file to find out how long a given package took to compile and also to estimate the time of future compile jobs, or you can use genlop, which is designed for the job.

Example of how it works:

  # genlop -nt kdelibs
Tue May  8 18:26:59 2007 >>> kde-base/kdelibs-3.5.6-r8
merge time: 38 minutes and 6 seconds.

This information can be used to estimate how long an update would take. The tool can be used to calculate the emerge time for a variety of package sets, like a world update, by calling it this way:
Example of emerging world:

# emerge -uDp world | genlop -p
These are the pretended packages: (this may take a while; wait...)
[ebuild     U ] app-office/openoffice-2.2.1 [2.2.0]
[ebuild     U ] media-libs/netpbm-10.39.0 [10.37.0]
Estimated update time: 5 hours, 50 minutes.

Now, what if you have a new package that you didn’t have installed, such as you want to install fluxbox on a machine that previously did not have X installed:
Example of using on a new package:

# emerge -p fluxbox | genlop -p
...
[ebuild  N    ] x11-libs/libXmu-1.0.3  USE="-debug -ipv6"
[ebuild  N    ] x11-apps/xmessage-1.0.1  USE="-debug -xprnt"
...
!!! Error: couldn't get previous merge of xmessage; skipping...
!!! Error: couldn't get previous merge of fluxbox; skipping...
...
!!! Error: fluxbox never merged; estimated time unknown.

Genlop will only reference the packages it knows. If you use the -q option (genlop version >= 0.30.7), an online database running on gentoo.linuxhowtos.org is queried for compile times based on users with an identical CPU to yours.
Above query results in:

# emerge -p fluxbox | genlop -p -q
These are the pretended packages: (this may take a while; wait...) ...
Estimated update time: 38 minutes.

The times are not 100% accurate; it does not respect USE flags or memory speed, hard disk speed, or other factors. However, as the times get averaged over different users, these factors become less important.

Source: Gentoo.org