Modify initrd.gz content

sudo gzip -d initrd.gz
sudo cpio -idm < initrd
...(Modify content)
sudo find . | cpio -o -H newc > initrd

avahi

Publish current information:

sudo avahi-publish -h ${host_name} -d ${domain_name} -s _${service_name}._tcp ${port_number} comment_1=${comment_1_context} comment_2="${comment_2_context_with_space}"

Collect information:

sudo avahi-browse -a -d ${domain_name} -r -p -t

Useful screen commands in byobu

CommandDescription

Ctrl + a, ?Show screen commands

Ctrl + a, |Split screen vertical

Ctrl + a, QShow current screen only

Ctrl + a, Ctrl + ISwitch focus screen

Ctrl + a, NumberSwitch to screen number X

Ctrl + a, CClean screen

Ctrl + a, x or Ctrl + xLock screen

Ctrl + a, k or KKill screen

Using lftp to mirror folder

Mirror CentOS repository from ftp.nchc.org.tw to local folder
sudo lftp -c mirror --continue --delete ftp://ftp.nchc.org.tw/pub/Linux/CentOS/ /mnt/mirror/CentOS/

Ubuntu wireless access point

Install hostaptd with command "sudo apt-get install -y hostapd"
Edit files as following.

File: /etc/default/hostapd
Content:

RUN_DAEMON="yes"
DAEMON_CONF="/etc/hostapd/hostapd.conf"
DAEMON_OPTS="-dd"

File: /etc/hostapd/hostapd.conf
Content:

interface=wlan0 # Please reference to your wireless device name.
driver=nl80211  # All support 802.11 spec. device can use the common driver.
hw_mode=g
channel=11
ssid=MySSID     # Please input SSID name that you would like to use.
wpa=1
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP CCMP
wpa_passphrase=MyPassword  # Please input your password for wireless access point.

Start service with one of the commands.

1. sudo service hostapd start
2. sudo hostapd -dd /etc/hostapd/hostapd.conf

Search linux command history by PageUp and PageDown

Edit /etc/inputrc and unmark lines as following.
”\e[5~”: history-search-backward
”\e[6~”: history-search-forward

Ubuntu Orchestra server config files

Global settings: /etc/cobbler/settings
Config path: /var/lib/cobbler/config
Template path: /etc/cobbler/*.template