My Little Book of Linux

********************** My Little Book of Linux *********************************

# Change hostname Ubuntu ###

hostnamectl set-hostname new-hostname

sudo nano /etc/cloud/cloud.cfg

# This will cause the set+update hostname module to not operate (if true)
preserve_hostname: true

# SSH Keys ###
Example!!!
ssh-keygen 
Create key 

ssh-copy-id ceph@ceph-deploy # admin mon
ssh-copy-id ceph@ceph-node1 
ssh-copy-id ceph@ceph-node2
ssh-copy-id ceph@ceph-node3
ssh-copy-id ceph@ceph-osd  #osd
Moves keys

# SUDO WITHOUT PASSWORD ###

echo "ceph ALL = (root) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ceph
chmod 0440 /etc/sudoers.d/ceph

# Change Time Zone ###

timedatectl set-timezone Africa/Johannesburg

# MYSQL ROOT ALL NODE ACCESS ###

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root';

# Adding a repo ###

wget -q -O- 'https://download.eu.ceph.com/keys/release.asc' | sudo apt-key add -
echo deb https://download.ceph.com/debian-luminous/ $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/ceph.list
apt update

# Fix Bad Sectors on Disks ###
as root

e2fsck -B ***** /dev/sda1 --- 2 options for blocksize pick one.

e2fsck -cfpv /dev/sda1


Docker save

docker save quay.io/coreos/flannel:v0.11.0-amd64 | gzip -c > flannel.tgz

gunzip -c flannel.tgz | docker load