Ben's notes

This pages describes the installation of CentOS 7 on PC Engines APU hardware.

• Connect a serial console, or USB↔Serial adapter. Make sure your locale is set to UTF-8.

  $ locale
  LANG="en_US.UTF-8"
  LC_COLLATE="en_US.UTF-8"
  LC_CTYPE="en_US.UTF-8"
  LC_MESSAGES="en_US.UTF-8"
  LC_MONETARY="en_US.UTF-8"
  LC_NUMERIC="en_US.UTF-8"
  LC_TIME="en_US.UTF-8"
  LC_ALL="en_US.UTF-8"

• If locale is not set right, add the following lines to your ~/.profile and login again.

  export LC_ALL=en_US.UTF-8
  export LANG=en_US.UTF-8

• Connect to serial console:

  screen /dev/tty.usbserial-A7022O5B 115200

• Edit /tftpboot/pxelinux.cfg/default:

  serial 0 115200
  default centos7
  prompt 0
  timeout 0
  
  label centos7
    kernel http://yourrepo.host/centos/7/CentOS7-base/images/pxeboot/vmlinuz
    append initrd=http://yourrepo.host/centos/7/CentOS7-base/images/pxeboot/initrd.img ks.device=bootif ip=dhcp ks=http://yourpxe.host/apu-centos7.ks console=ttyS0,115200

• Edit kickstart file apu-centos7.ks:

  ####
  #### PC Engines APU KickStart installation
  ####
  install
  
  # Base repo
  url --url=http://repo/centos/7/CentOS7-base
  # Configure updates repo
  repo --name="CentOS7-updates"  --baseurl=http://repo/centos/7/CentOS7-updates
  
  network --onboot yes --bootproto dhcp
  lang en_US.UTF-8
  keyboard --vckeymap=us --xlayouts='us','us'
  rootpw --iscrypted <sha512 password hash>
  firewall --service=ssh
  authconfig --enableshadow --passalgo=sha512
  selinux --enforcing
  timezone --utc Europe/Amsterdam
  
  # Set serial console and change disk elevator to noop for SSD.
  bootloader --location=mbr --driveorder=sda --append="console=tty0 console=ttyS0,115200 elevator=noop rd_NO_PLYMOUTH"
  
  # Any disks whose formatting is unrecognized are initialized.
  zerombr
  
  # Erases all partitions from the system.
  clearpart --all --drives=sda --initlabel
  
  # Initialize boot partition.
  part /boot --fstype=xfs --size=512 --asprimary
  
  # Create LVM pv and vg.
  part pv.01 --size=1000 --grow --asprimary
  volgroup vg pv.01
  
  # Create lv's, set discard, noatime and commit time. Leave some space left in the VG for later use.
  logvol swap  --vgname=vg --size=512  --name=lv_swap --fstype=swap
  logvol /     --vgname=vg --size=4096 --name=lv_root --fstype=xfs
  logvol /var  --vgname=vg --size=4096 --name=lv_var  --fstype=xfs
  logvol /home --vgname=vg --size=512  --name=lv_home --fstype=xfs
  
  # Create non administrative user
  user --name=username --homedir=/home/username --password=<sha512 password hash>
  
  # Reboot after installation.
  reboot
  
  # Install minimal, exclude @Base, exclude documentation
  %packages --nobase --excludedocs
  @Core		#default
  bind-utils      #dig, host, nslookup
  openssh-clients #ssh client, key agent, sftp, scp
  nc		#nc (netcat)
  %end
  
  %post
  # Disable SSH root login
  /bin/sed -i.bak 's/#PermitRootLogin yes/PermitRootLogin no/g' /etc/ssh/sshd_config
  
  # Mount /tmp as tmpfs.
  systemctl enable tmp.mount
  
  #Add weekly fstrim job
  cat << EOF >  /etc/cron.weekly/fstrim
  #!/bin/sh
  #this script will run weekly, will overwrite log.
  
  trimlog=/var/log/fstrim.log
  echo > \$trimlog
  for fs in \$(lsblk -o MOUNTPOINT,DISC-MAX,FSTYPE | grep -E '^/.* [1-9]+.* ' | awk '{print \$1}'); do
    printf "\`date\` - \`fstrim -v \$fs\`\n" >>\$trimlog
  done
  EOF
  chmod +x /etc/cron.weekly/fstrim
  
  # Enable LVM to issue discards.
  /bin/sed -i.bak 's/issue_discards = 0/issue_discards = 1/g' /etc/lvm/lvm.conf
  
  # Reduce swappiness.
  echo "vm.swappiness=1" >> /etc/sysctl.d/swappiness.conf
  echo "vm.vfs_cache_pressure=50" >> /etc/sysctl.d/swappiness.conf
  
  # Set chassis name and icon
  /bin/hostnamectl set-chassis "server"
  
  exit 0
  %end

• Boot the APU and press F12, select “iPXE” to boot from network.