Linux Tricks

1. Disable Ipv6 on CentOS 8
2. LVM Extend
3. apt update NO_PUBKEY
4. AKS from az CLI

Disable Ipv6 on CentOS 8

Create disableipv6.conf file on /etc/sysctl.d directory:

vi /etc/sysctl.d/disableipv6.conf

Add this next 2 lines in disableipv6.conf:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

If you need disable Ipv6 only in one interface use the next line arg(enp0s3 in example):

net.ipv6.conf.enp0s3.disable_ipv6 = 1

Restart sysctl service:

systemctl restart systemd-sysctl

LVM Extend

Create partition 8e type with fdisk.

Create a physical volume:

pvcreate /dev/sdXx

Add physical volumes to a volume group:

vgextend vg_name /dev/sdXx

Extend a logical volume: (use 100% free space of volume group to logical volume)

lvextend -l +100%FREE /dev/vg_name/volume_name

(define the new size of logical volume to 542Gb)

lvextend -L 542G /dev/vg_name/volume_name

(add 1Gb to logical volume)

lvextend -L +1G /dev/vg_name/volume_name

Increase de file system size: (for XFS file system)

xfs_growfs /mount/point -D size - xfs_growfs /mount/point

(for EXT file system)

resize2fs /mount/point

apt update NO_PUBKEY

Error NO_PUBKEY

"The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5BA31D57EF5975CA"

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 5BA31D57EF5975CA

AKS from az CLI

az aks command invoke --resource-group nome-rg --name nome_aks --command "kubectl get pods -A"