KfWiki: Linux Area

Linux Area

Terminal Kernel Boot Filesystem Samba
Security XWindows USB Language Printing
Installation Grub single user mode Fonts RPM Compilation
Rsync Sudo SNMP Sound with OSS NIC Bonding
strace KickStart DVDWriting LTSP Compile Wine
ProcFS Benchmark Multimedia NetTuning WirelessNetworking Sensors Custom Repo Mouse

Distribution specific

Ubuntu
Debian
Redhat
Fedora
CentOS
SuSe
Knoppix

Adding additional repository to yum

Repositories:

DAG
GStreamer

More on YUM

Install yum-skip-broken such that you can add --skip-broken switch to yum. Find yum-skip-broken rpm from your favorite rpm search site.

Configure options I used for various software

Configure

ipcs

The ipcs utility lists the opened semaphores.

ipcs

To remove semaphores owned by the user "www"

ipcs|grep www|awk '{print $2}'|xargs -n 1 ipcrm -s

Fast way to add swap

Create a 1G swap file

dd of=/.swap01 bs=1k count=0 seek=1M
mkswap /.swap01
swapon /.swap01

rsync & ssh

rsync -avvxz -e ssh source_file root@1.2.3.4:/dest/dir

DST fix for Redhat 9

1. Downloaded the tzdata2007c.tar.gz file from /pub/ at elsie.nci.nih.gov.
2. Extracted the tar.gz file:
3. Used zic to create the new zoneinfo file:
# zic -d zoneinfo northamerica
# cd zoneinfo
# cp -r * /usr/share/zoneinfo/

3. Typed zdump -v CST6CDT | grep 2007 to confirm that the DST patch had been applied. Results:
CST6CDT Sun Mar 11 07:59:59 2007 UTC = Sun Mar 11 01:59:59 2007 CST isdst=0 gmtoff=-21600
CST6CDT Sun Mar 11 08:00:00 2007 UTC = Sun Mar 11 03:00:00 2007 CDT isdst=1 gmtoff=-18000
CST6CDT Sun Nov 4 06:59:59 2007 UTC = Sun Nov 4 01:59:59 2007 CDT isdst=1 gmtoff=-18000
CST6CDT Sun Nov 4 07:00:00 2007 UTC = Sun Nov 4 01:00:00 2007 CST isdst=0 gmtoff=-21600

More information on zdump

zdump -v /etc/localtime EST5EDT | grep 2007

is what you would use for the U.S. Eastern time zone. If you're in the Central time zone, use CST6CDT; in the Mountain time zone use MST7MDT; and in the Pacific time zone, use PST8PDT.

If your system is set up properly, it will return a display that starts with two lines containing "Sun Mar 11". If, instead, you see a pair of lines with "Sun Apr 1" within them, you'll need to do a manual update.

Static routes

On Redhat, create a file /etc/sysconfig/network-scripts/route-eth0 with the following content. Note: /etc/sysconfig/static-route no longer works.

192.168.7.0/24 via 192.168.1.254

Redhat says it should be this. http://kbase.redhat.com/faq/FAQ_45_9670.shtm

GATEWAY0=192.168.1.1
NETMASK0=255.255.255.0
ADDRESS0=10.10.10.0

GATEWAY1=192.168.1.1
NETMASK1=255.255.255.0
ADDRESS1=20.20.20.2

On FreeBSD, add a static route to network in rc.conf:

static_routes="rsite1"
route_rsite1="-net 192.168.7.0 192.168.1.254 255.255.255.0"

MTU size

Experiment with the ping -s option

ping -s 1464 1.2.3.4

preload

http://www.techthrob.com/tech/preload.php

max arguments

If you run into argument list too long, the following probably won't help you. Pipe your output to xargs.

# getconf ARG_MAX
2097152

# sysctl kern.argmax
kern.argmax=2097152

find and xargs

These are the tools that most linux administartors will be familiar with. Here are some interesting options:

tool	option	meaning	default
xargs	-n 99	number of arguments to pass at a time	na
xargs	-P 99	number of processes to spawn	1

Capturing mouse / keyboard event under X

use xev

Obtain hardware infomation

dmidecode

Create ISO image

mkisofs -l -J -L -r -o output.iso file_list

SELinux

I know nothing about SELinux, always has it disabled.

http://www.linuxdevcenter.com/pub/a/linux/excerpt/selnx_1/index.html

Plesk

It does not belong to anywhere so I'll just put it here.
http://rackerhacker.com

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