{{parent page="Linux"}}
===Ubuntu specific knowledge===

==[[UbuntuNicBonding Ubuntu Nic Bonding]]==
==[[UbuntuTop10Todo Ubuntu Top 10 Todo]]==

==cool howto's==
http://www.howtoforge.com/how-to-add-a-splash-image-to-grub-2-on-ubuntu-9.04

==boot faster==
http://www.linuxlinks.com/article/20090927065957648/UbuntuTips-Booting-Part3.html
Edit /etc/init.d/rc
%%
CONCURRENCY=shell
%%

==Iptables==
To load iptables on boot, edit /etc/network/interfaces as follow:

%%
auto eth0
pre-up iptables-restore < /etc/iptables
post-down iptables-restore < /etc/iptables
%%

==Installing cisco vpn client==
Patching required. Good link at http://popey.com/Cisco_VPN_client_under_Ubuntu_6.06_@LTSA_Linux

==scim==
https://help.ubuntu.com/community/SCIM

==Raid and LVM==
===Root filesystem on raid/lvm===
See SoftwareRAID That's the easy part. The difficult part is to get initramfs to do all the raid/lvm work, such as scanning raid devices and activating vg, etc. I have no idea why this is not working by default or why the ubuntu desktop installer does not support raid/lvm. They key points are:
1. /etc/fstab should mount the raid partition as /. This is read by mkinitramfs / mkinitrd
2. /etc/mdadm.conf should be current and the uuid must be correct
3. /etc/initramfs.d/module should contain "raid1" if you are using mirror

Then run mkinitramfs.

===/boot on raid ===
see LinuxGrub2

===Kernel===
Ref: https://help.ubuntu.com/community/Kernel/Compile
Also check out the kernelcheck project.

Step 0: Backup /boot. This is important dude!
%%
aptitude install kernel-package fakeroot
cp /boot/config-whatever .config
make menuconfig
%%
Turn off kernek debugging to reduce the image size: go into "Kernel hacking"; then, under "Kernel debugging", turn OFF "Compile the kernel with debug info".

%%
export CONCURRENCY_LEVEL=4
make-kpkg clean
DEB_BUILD_OPTIONS=parallel=4 fakeroot make-kpkg --initrd --append-to-version=-rt kernel-image kernel-headers
#echo vesafb >> /etc/initramfs-tools/modules
#echo fbcon >> /etc/initramfs-tools/modules
cd /usr/src
dpkg -i linux-headers-2.6.30.4_2.6.30.4-10.00.Custom_amd64.deb linux-image-2.6.30.4_2.6.30.4-10.00.Custom_amd64.deb
%%

check grub.cfg and then reboot.

===Skipping packages in update manager===
Open synaptic package manager, select upgradable packages, then go to package > lock version. Seems to me it's actually adding a regex to a file. The following contains packages I want to exclude (linux kernel).

%%
# /etc/apt/apt.conf.d/05aptitude
aptitude::Keep-Unused-Pattern "^linux-image.*$ | ^linux-restricted-modules.*$ | ^linux-ubuntu-modules.*$";
aptitude::Get-Root-Command "sudo:/usr/bin/sudo";
%%

Similarly, one may use the hold and unhold command from aptitude to prevent safe-upgrade from installing certain packages
%%
aptitude hold linux-image
%%

Check packages that have been held:
%%
# dpkg --get-selections | grep hold
linux-generic hold
linux-headers-generic hold
linux-image-generic hold
linux-libc-dev hold
linux-restricted-modules-common hold
linux-restricted-modules-generic hold
%%


===if-up.d===
ok weird things about files in this directory. I added a script to set up txqueuelen but it was not ran or it's being overwritten. somehow, I changed ntpd to not run in the background (by removing & at the end) and that solved the problem. Perhaps runparts dies when it encounter an error or something. Anyway, that may also be why my nfs mounts are not brought up on boot because of files in this directory.


===dist upgrade from 9.04 to 9.10===
Don't do it unless you can afford it.

%%
update-manager -d
aptitude clean
aptitude autoclean
apt-get autoremove
aptitude install -f
aptitude update
aptitude safe-upgrade
%%