This is an old revision of the document!
Welcome to my gnulinux wiki page. Tis page has simple and complex system administrationnotes to remind me when I forget something that I already learned! If you are visiting, I hope you find the page useful.
#optical media ripping from command line
cdrecord -pad -dao -data blag-140k-i686.iso
#security & policy information
sudo nano /etc/pam.d/common-password
Prevent Log in - create file
/etc/nologin
tcpdump common uses; monitoring traffic on network
tcpdump -n -i <eth0> <host> <x.x.x.x> tcpdump -n -i <eth0> <port> <#> tcpdump -i eth0 -nn -c 10 tcp and host <x.x.x.x> tcpdump -i wlan0 port http or port smtp or port imap or port pop3 -l -A | egrep -e 'pass=|pwd=|log=|login=|user=|username=|pw=|passw=|passwd=|password=|pass:|user:|username:|password:|login:pass |user |Referer:'
#display managers; lightdm & gdm3
cd /usr/share/lightdm/light.conf.d/
Global lightdm settings here
cd /etc/lightdm/ sudo nano lightdm.conf
Lightdm ubuntu-MATE greeter and lock screen issues
/usr/share/common/backgrounds/ubuntu-mate-common/Ubuntu-Mate-Cold.jpg /etc/lightdm/lightdm-gtk-greeter.conf
The .conf file w/ some common sense parameters
[SeatDefaults] allow-guest=false greeter-hide-users=true
#miscellaneous sysadmin easy
start or stop network manager (or other services)
systemctl <start/stop/restart> networkmanager.service /etc/init.d/network-manager <start/stop/restart>
verify dhcp client working for interface eno1
dhclient -v eno1
add subnet to interface eno1
ip address add 192.1##.1##.2/24 dev eno1
interface tool w/ eno1 example
ethtool eno1
interface with switch using screen
screen /dev/ttyUSB0/ 19200
calculate subnet automatically
subnetcalc
proxying web traffic through remote server
ssh -D <port#> <user>@<domain.com>
get block ID of drives
blkid
nmap to scan devices on lan
nmap -sP 10.##.##.0/24
find utils example
find . -iname "name"
#scripts and miscellaneous
downloading scripts and executing them; example from DO
curl -sSL https://agent.digitalocean.com/install.sh | sh
ngrok notes; private http(s) tunnels
./ngrok http 80 wget https://[ngrok tunnel]/id_rsa.pub cat ~/id_rsa.pub >> ~/.ssh/authorized_keys
query hosts on the lan
avahi-browse -tl _workstation._tcp
Debian print system configuration to stdout; use root
cat /proc/cpuinfo && lspci | grep -i vga && uname -a && lsb_release -a lsb_release -a lspci
Debian repo management
cd /etc/apt nano sources.lsit [main contrib non-free]
Uploading files to remote webservers with sftp
cd ~/Downloads sftp user@host.com:/path/to/sftp/directory/of/choice/ > put /path/to/file.txt
#Building From Source to Custom library Location
tar -xf <source_filename>
Navigate to the directory that tar unarchived the files to. Then, within that directory, execute:
./configure --prefix=/usr/local make sudo make install clean
#virt-manager stuff
Start defualt
sudo virsh net-start default
Remove bridge
sudo ifconfig virbr0 dow sudo brctl delbr virbr0
List all
sudo virsh net-list --all
#rsync
sudo rsync -avxHAX --progress /sourcefiles/path /backup/path
#Simple Bridge Mode Virt-Manager
create it - use gui, or brctl
sudo nano /etc/network/interfaces
auto br1 iface br1 inet dhcp bridge_ports enp3s0 bridge_stp on bridge_fd 0.0
#smart tests
smartctl -t short smartctl -t long
#ssh with screen
ssh -t xx.xx.xx.xx screen -DRO
#RAID 1 Notes
The sfdisk command is not complete … the proc shows kernel report on mirroring / syncing status …
sfdisk -d | sfdisk cat /proc/mdstat
Temperamental Swap mirroring …
mdadm –readwrite /dev/md1
#Purism Keyboard Issue
sudo nano /etc/rc.local
Put this in the file.
#!/bin/sh setkeycodes 56 43 exit 0
Ctrl-X, Y, Enter.
sudo chmod 750 /etc/rc.local sudo chown root:root /etc/rc.local sudo reboot
Done - problem fixed.
#Level 3 DNS & resolv.conf
sudo nano /etc/resolv.conf search domain.com [local domain] nameserver xx.xx.xx.xx [router] nameserver 4.2.2.1 nameserver 4.2.2.2 nameserver 4.2.2.3 nameserver 4.2.2.4
#next topic
— oemb1905 2018/03/15 00:23