RHEL/CentOS

Configure a Postfix Relay through Gmail on CentOS 7

When installing on VMware, add the following line to fix the screen resolution: vga=794

Installer window is not displayed properly during RHEL 6.1 and CentOS 6.3 guest operating system installation, missing Next button (2003588)

Bare metal and Virtual Machine Provisioning through Foreman Server

Create LVM Volume

   # pvcreate /dev/sdb1
   # vgcreate opt_vg /dev/sdb1
   # lvcreate -n opt_lv -l 100%FREE opt_vg

Using Packer to create a VM with the [1](packer-builder-vsphere) plugin.

{
 "builders": [
   {
     "type": "vsphere-iso",
     "boot_command": [
       "<tab> text ks=hd:fd0:/KS.CFG<enter><wait>"
     ],
     "boot_wait": "10s",
     "vcenter_server": "",
     "username": "[email protected]",
     "password": "",
     "insecure_connection": "true",
     "vm_name": "test-centos7",
     "cluster": "Production",
     "datastore": "vm-storage",
     "guest_os_type": "rhel7_64Guest",
     "ssh_username": "root",
     "ssh_password": "",
     "CPUs": 2,
     "RAM": 2048,
     "RAM_reserve_all": true,
     "disk_controller_type": "pvscsi",
     "disk_size": 32768,
     "disk_thin_provisioned": true,
     "network_card": "vmxnet3",
     "network": "Management",
     "iso_paths": [
       "[ISOs] Linux/CentOS/CentOS-7-x86_64-NetInstall-1804/CentOS-7-x86_64-NetInstall-1804.iso"
     ],
     "floppy_files": [
       "ks.cfg"
     ]
   }
 ],
 "provisioners": [
   {
     "type": "file",
     "source": "CentOS-Base.repo",
     "destination": "/tmp/CentOS-Base.repo"
   },
   {
     "type": "shell",
     "inline": ["rm /etc/yum.repos.d/CentOS-Base.repo && cp /tmp/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo && yum update -y && yum install -y vim bash-completion"]
   }
 ]
}

Install VirtualBox guest additions on CentOS Stream 9:

 # dnf -y install gcc make bzip2 tar kernel-devel elfutils-libelf-devel
 # mount /dev/cdrom /mnt
 # cd /mnt
 # ./VBoxLinuxAdditions.sh