steveL's favourite tips

steveL · Posted: Sun Jan 07, 2007 7:28 am Post subject: steveL's favourite tips

I'm just collecting stuff I've learnt from others here, so it's all in one place in case I lose all my data and hopefully it'll be of use to others.
Top tip so far:
If you have a problem with software in portage file a bug with a patch to add whatever it is that's missing. Be aware of bugzilla ettiquette -- it's not a place for discussion unless it's technical and specific to the bug. If you're unhappy with how you're dealt with, discuss it on the project mailing-list if you don't feel able to file a userrel or devrel bug.
Installation
Understanding the boot process
Rough Guide to Kernel Building
- to search for CONFIG_NET_WIRELESS, press / and then type NET_WIRELESS in the resulting dialog
- nowadays we just use make nconfig
lspci -k to see what modules the live-disk kernel uses for your devices.
Setting up hard-drives (migration to libata, but covers it all afaict.)
Troubleshooting hard-drives: megaSAS in this case, but great overview of how to chase down issues.
UEFI and nvidia
Resuming an Install
Salvaging an Install
Fix Networking
Don't forget to set your hostname
Xorg Modelines (last resort: start with a blank config, as X should work out of the box)
X for 3d cards: ATI needs DRI loaded, nvidia needs DRI unloaded. (correct me if any of this seems wrong)
USB-2 and USB-3 working together
Dual-booting Windows (Win7 and MBR specifically, but good discussion overall); see here for Win 8.1 EFI.

Maintenance
The basics
Tweaking your install
use FEATURES=buildpkg to keep backups of all emerged packages so you can rollback in case of problems.
- you can also use this to build binary packages for multiple machines
Cleaning out logfiles
Getting portage messages for an emerge
Use update
- by default does our system update procedure:
emerge -uDN @world --with-bdeps y
(with --pretend first, to review the list: recommended procedure)
- review and edit USE flags on a per-package basis, or globally, by pressing E for the edit list dialog.
- followed by:
glsa-check
depclean
@preserved-rebuild (if required)
revdep-rebuild
- to get the same with --changed-use use: update -auDU

To run: emerge -uD --changed-use @world without bdeps, use: update -auDU @world
..and take out the a if you just want to run it without confirming. It supports parallel builds.

Full procedure without bdeps: update -auDN --bdeps=n

IOW: if you give it a parameter like a pkg-name, it just wraps emerge. If not, it does a system upgrade.
except: you have to tell it to install a package to world with -i, eg: update -ia kate
By default it just updates the package, ie: emerge -1 package which pulls in needed dependencies, with your flags.

Recover from a snafu see also Reinstalling python on next page.
in the cli: euse -i USEFLAG is your friend
Listing overlay packages
to check whether you have a module:
lsmod = loaded modules, modprobe -l = all built modules
- just add |grep -F module to find it if you have a specific module in mind.

How to use dep? (The man page is hard when you're tired) Top 3 thanks to mark_alec on IRC
dep -w, --pruneworld
dep -u, --usedesc for PKG
dep -e, --versions and status of PKG
-t, --tree-depends and -T, --reverse-tree of PKG
-U, --iuse list pkgs which declare a USE flag
- kudos to ecatmur for the script.

mount -t smbfs -o lfs allows large files (IRC)

For archive: no name, took it down a while ago, sorry:
Let's assume you want to write /usr/local into a file under /mnt/archive:
find /usr/local -print | cpio -H tar -ov | bzip2 > /mnt/archive/usr_local.tar.bz2
To list the contents of your archive:
bunzip2 -c /mnt/archive/usr_local.tar.bz2 | cpio -itv
To extract the archive, you can use:
bunzip2 -c /mnt/archive/usr_local.tar.bz2 | cpio -imdv
Now, let's assume your /usr/local/ contains the file /usr/local/bin/myscript. You can extract just this file by:
bunzip2 -c /mnt/archive/usr_local.tar.bz2 | cpio -imdv /usr/local/bin/myscript
or even extract all of your scripts that start with "my":
bunzip2 -c /mnt/archive/usr_local.tar.bz2 | cpio -imdv '/usr/local/bin/my*'
Note the quotes on the pattern so the shell doesn't interpret it.

AFAIR, there are some older versions of cpio, in which the -H tar didn't preserve the modification time correctly.
I usually prefer option -c or -H crc, which are, however, not compatible with tar.
cpio has many other interesting options, so it's worth having a look at the manpage.

Advanced usage
How to get a package stabilised
Daemonizing azureus - example initscript
Per-package CFLAGS using package.env. If that makes no sense, you should wait till you know Gentoo better.
Sneakernet (no-net install)
Read-only root eg SD-card
Building in a chroot snapshot using BTRFS.

Adding patches to an ebuild:
First try to see if the ebuild supports epatch_user already: if it inherits from eutils (perhaps indirectly) then it will.
Support for apply_user_patches has been proposed for EAPI 6.

You can also use the post_src_unpack() user hook and the profile.bashrc in the
base profile for this. E.g.:

Fukai · Posted: Sun Jan 07, 2007 5:19 pm Post subject: Re: steveL's favourite tips

steveL · Posted: Sun Jan 07, 2007 7:14 pm Post subject:

Nice one Fukai.

steveL · Posted: Tue Jan 09, 2007 11:22 am Post subject:

First, emerge gentoolkit if you don't have it (you should!)

# Check for security updates:
glsa-check -l affected

# Check which packages will be emerged :
glsa-check -p affected

# Apply security updates:
glsa-check -f affected

Thanks lefou!

steveL · Posted: Wed Jan 10, 2007 2:59 pm Post subject:

Having device nodes for stuff udev doesn't handle:
<Kyuu> ..a tarballed udev tree which can be set in /etc/conf.d/rc
<MvG> RC_DEVICE_TARBALL="yes"
from rc file:
# Set to "yes" if you want to save /dev to a tarball on shutdown
# and restore it on startup. This is useful if you have a lot of
# custom device nodes that udev does not handle/know about.
<MvG> You create the device node manually, and next time you reboot it's recreated from the tarball.

steveL

awk 'sub(/-[0-9].*/, "")' is the current recommendation for a pipe/ file of pkg names
[${x%-[0-9]*} if $x has the atom (I haven't tried this yet, but I trust xmb on #bash)

nanafunk · n00b Joined: 29 Jun 2005 Posts: 36

Don't trust xmb.

lefou · Posted: Wed Jan 10, 2007 8:28 pm Post subject:

steveL · Posted: Thu Jan 11, 2007 3:40 am Post subject:

nanafunk · n00b Joined: 29 Jun 2005 Posts: 36

2 functions from my ~/.bashrc, hopefully some use to someone.

pc -- package count, number of packages installed
pl -- package list, list of packages installed

steveL · Posted: Fri Jan 19, 2007 3:01 am Post subject:

Excellent! Thanks nanafunk.

steveL · Posted: Mon Jan 29, 2007 7:35 pm Post subject:

steveL · Posted: Wed Feb 07, 2007 1:39 pm Post subject: speeding up portage

Note this is now the default method in portage (and has been for a few years.)

This is an excellent tip from zmedico for speeding up portage cache updates- by not doing them! Seems the metadata kept in /var/cache/edb is pretty similar to the metadata which is rsynced (slightly different format) and portage can be set just to use the rsynced version. Perfect!

All you do is:

steveL · Posted: Tue Mar 06, 2007 5:04 am Post subject:

Transferring system:
from uberpinguin:
I have had excellent results from booting off a livecd, and 'tar -vcpj /mnt/gentoo/ --file=/remote/volume'. Never had trouble with the restore.

boot from a livecd, mount your root filesystem in /mnt/gentoo/ and 'tar -xvcjpf /remote/volume/archive.tar.bz2 /mnt/gentoo/'

N-S · n00b Joined: 30 Oct 2005 Posts: 34

Link to Sneakernet is broken. It goes to the Xorg modelines page.
_________________
___________________
There is No Substitute!

steveL · Posted: Sun Mar 11, 2007 5:50 pm Post subject:

steveL · Posted: Wed Mar 14, 2007 10:49 am Post subject:

steveL · Posted: Thu Mar 15, 2007 3:46 pm Post subject:

TriffidHunter: ..when you don't put INPUT_DEVICES="mouse keyboard" in your make.conf before emerging xorg.. add that, then emerge -avt1 xf86-input-{mouse,keyboard}

intel hd audio: if (kernel alsa) the modem driver (Intel/SiS/nVidia/AMD MC97 Modem) is enabled i cannot use my soundcard either (renihs)
zgrep SND_INTEL8X0M /proc/config.gz (zlin) good tip for checking whether your kernel has a setting.

steveL · Posted: Mon Apr 30, 2007 10:01 am Post subject:

steveL · Posted: Mon Apr 30, 2007 10:02 am Post subject:

Another NeddySeagoon post, this one on setting up IDE and DMA for hard disk and cdroms. Change the chipset line at the bottom to match yours.

steveL · Posted: Mon Nov 26, 2007 4:33 pm Post subject: Setting up a local overlay

This is really simple, but there's a small gotcha, which is you need a repo_name file in profiles subdir, or portage will complain that the PORTDIR directory structure is invalid. Secondly, there's no more old-style make.conf PORTDIR_OVERLAY="/usr/local/portage", and we need to give it a layout.conf. The Wiki has a page on this, so check that too.

We normally use: /usr/local/portage since that keeps it out of the portage tree (eg if we want to use a different fs for the tree, or wipe it and reformat, when distfiles is another mount), and is in the correct place for just this machine:

steveL · Last edited by steveL on Sat Mar 08, 2014 7:01 pm; edited 4 times in total

To get anything you emerge with FEATURES=debug emerge blah to also have the proper CFLAGS etc for a debug build, use this in /etc/portage/bashrc:

steveL · Posted: Mon Dec 03, 2007 3:06 pm Post subject: Using dispatch-conf

Thargor: Just use dispatch-conf.
/etc/dispatch-conf.conf:

steveL · Posted: Wed Dec 05, 2007 2:55 pm Post subject: Using gentoo in production

Nice post which gives a good summary of how to setup Gentoo in production. update handles binpkgs nicely ofc :)

steveL · Last edited by steveL on Wed Oct 30, 2013 9:21 pm; edited 1 time in total

Great post on making an updated install stage. I've been building chroots for the last couple of months while working on update and am thinking to write a script to replicate my current setup from a stage3. I've built loads of chroots, especially since I started using a binhost, and have started a script which takes care of the base build based on user menu selection.
Anyhow, I'll add stuff to this post, so far we have:

Hostname, and configs
We can copy from existing system, or the config file dir. And the user should be able to edit any config file from a selection and revert changes in case of problems. Eg making sure the CFLAGS are correct (for a single-user reinstall) is important, as are any base USE settings.
Update system then emerge -e world
First run of system and world we can do -X, imo. It's better to build it up slowly, get the machine booting and see.
umount /dev /proc from the chroot and then tar the installation (this is within chroot):

Code:

cd / && tar -cvjp ./ -f $(date +%Y%m%d)-baseline.tar.bz2

Gives a base stage. It would be fun to play with that in a vm as well.