KPTree Home Server Setup

Basic Network Setup

To check available interfaces and names: "ip link"

Ensure the bridge utilites are loaded: "sudo apt install bridge-utils"

Edit the network configuration file: "/etc/network/interfaces" as follows:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
# auto eth0
# iface eth0 inet dhcp

#Basic bridge setup on a NIC to allow virtual machine NIC access
#The DHCP server is used to assign a fixed IP address based upon MAC
auto br0
iface br0 inet dhcp
        bridge_ports eth0
        bridge_fd 9
        bridge_hello 2
        bridge_maxage 12
        bridge_stp off

#No point enabling NIC that are not being used
#auto eth1
#iface eth1 inet manual

#auto eth2
#iface eth2 inet manual

#auto eth3
#iface eth3 inet manual

I tried earlier to use static assigned IP setup, but had problems with operation and used setup with dhcp, which worked. I then setup the dhcp sever to assign a fix IP address to the eth0 address.

Full Network Setup

As noted in the main section I have a server with 4 built in Intel NICs. To reduce performance reduction due to limited Ethernet bandwidth using only one NIC I propose to use 2 NICs in bonded configuration and also use bridging to allow server virtual machine access to the NICs and also use the remaining 2 NICs effectivily as a switch.

To check available interfaces and names: "ip link"

Ensure the bridge utilites are loaded: "sudo apt install bridge-utils"

The bonded configuration needs ifenslave utility loaded: "sudo apt install ifenslave"

My NIC connectors are setup as follows:

 IPMI_LAN
 USB2-1   USB3-1   LAN3(eth2)   LAN4(eth3)
 USB2-0   USB3-0   LAN1(eth0)   LAN2(eth1)   VGA

Edit the network configuration file: "/etc/network/interfaces" as follows:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5)
# and brctl(8).
# The loopback network interface
auto lo
iface lo inet loopback

#Setup the Bond
auto bond0
iface bond0 inet manual
hwaddress ether DE:AD:BE:EF:69:01
post-up ifenslave bond0 eth0 eth1
pre-down ifenslave -d bond0 eth0 eth1
bond-slaves none
bond-mode 4
bond-miimon 100
bond-downdelay 0
bond-updelay 0
bond-lacp-rate fast
bond-xmit_hash_policy layer2+3
#bond-mode 4 requires that the connected switch has matching
#configuration

#Start Bond network interfaces in manual
auto eth0
iface eth0 inet manual
bond-master bond0

auto eth1
iface eth1 inet manual
bond-master bond0

#Setup Bridge Interface
auto br0
iface br0 inet static
address 192.168.1.5
network 192.168.1.0
netmask 255.255.255.0
broadcast 192.168.1.255
gateway 192.168.1.1
dns-nameservers 192.168.1.1
bridge_ports bond0 eth2 eth3
bridge_stp off
bridge_fd 9
bridge_hello 2
bridge_maxage 12

The following is a description of some of the parameters

• Bonding
  • bond-mode
    • balance-rr or 0 (default) is a good general option
    • 802.3ad or 4 requires a switch that is corespondingly setup with IEEE 802.3ad Dynamic link aggregation.
  • bond-lacp-rate, only required for 802.3ad mode, Option specifying the rate in which we'll ask our link partner to transmit LACPDU packets, default is slow or 0:
    • slow or 0, Request partner to transmit LACPDUs every 30 seconds
    • fast or 1, Request partner to transmit LACPDUs every 1 second
  • bond-xmit_hash_policy
    • layer2 (default)
    • layer2+3
    • layer3+4

  layer2 and layer2+3 options are 802.3ad compliant, layer3+4 is not fully compliant and may cause problems on some equipment/configurations.

  • bond-slaves
  • bond-master
  • hwaddress ether xx:xx:xx:xx:xx:xx
    • The MAC address xx:xx:xx:xx:xx:xx must be replaced by the hardware address of one of the interfaces that are being bonded or by a locally administered address (see this Wikipedia page for details). If you don't specify the Ethernet address then it will default to the address of the first interface that is enslaved. This could be a problem as it is possible for various reasons that the hardware address of the bond could change, and this may cause problems with other parts of your network.

Bonding Benefits and Limitations

• Benefits
  • Increased Ethernet speed/bandwidth (with limitations)
  • Link Redundancy (not a feature of particular interest to me)
• Limitations
  • More complex setup
  • Not as fast and flexible as faster ethernet connection as each transport connection only uses one media connection to prevent packet mixup, hence maximum connection speed limited to speed of one bond lane

Modern harddisks are generally faster than a 1 Gb/s ethernet connection, SSDs significantly so. Yet many individual data demand usages are significantly slower, e.g. video 0.5 to 30Mb/s, audio 100 - 400 kb/s. Furthermore most external internet connection are still normally slower then 100Mb/s, with only larger offices having 1Gb/s or more bandwidth. So the biggest speed/time impact is when coping files across a speed limited ethernet LAN connection or where a server is used to provide information to multiple clients. Ethernet bonding can help improve server performance by sharing multiple simultaneous client connections between the bonded ethernet connections.

Wifi quoted speeds are particularly bogus / optimistic. The quoted speed is usually the best possible speed achievable. Wifi bandwidth is often shared with many simultaneous users, with each n user only often getting at best a 1/n share of bandwidth. There are also latency and interferance issues with Wifi that can affect performance. Wired LAN ethernet connection tend to provide more reliable consistent performance. That being said Wifi is convenient and in most, but certinly not all, cases fast enough.

Full Network Setup 18.04

This is the setup for my new server with 4 built in Intel NICs, with Ubuntu 18.04 To reduce performance reduction due to limited Ethernet bandwidth using only one NIC I propose to use 2 NICs in bonded configuration and also use bridging to allow server virtual machine access to the NICs and also use the remaining 2 NICs effectivily as a switch.

To check available interfaces and names: "ip link"

Netplan does not require the bridge utilites to be loaded however these utilities can be used upon the bridge: "sudo apt install bridge-utils"

Under netplan the bonded configuration does not need ifenslave utility loaded, as this utilities is dependant upon ifupdown. Do not install "sudo apt install ifenslave"

The netplan website with basic information netplan.io. Also another resource is from cloud-init Networking Config Version 2

My new server NIC connectors are setup as follows:

 IPMI_LAN
 USB2-1            LAN3(eno3)   LAN4(eno4)
 USB2-0            LAN1(eno1)   LAN2(eno2)   VGA

As instructed in the system created yaml file "/etc/netplan/50-cloud-init.yaml", create the file "sudo vim /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg" and add the line "network: {config: disabled}"

Edit the network configuration file: "/etc/netplan/interfaces.yaml" as follows:

network:
  #setup network interfaces
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      dhcp4: no
      dhcp6: no
      optional: true
    eno2:
      dhcp4: no
      dhcp6: no
      optional: true
    eno3:
      dhcp4: no
      dhcp6: no
      optional: true
    eno4:
      dhcp4: no
      dhcp6: no
      optional: true
  #Setup the Bond
  bonds:
    bond0:
      interfaces: [eno1, eno2]
      parameters:
        mode: balance-rr
  #Setup Bridge Interface
  bridges:
    br0:
      addresses: [192.168.1.10/24]
      interfaces: [bond0, eno3, eno4]
      gateway4: 192.168.1.1
      nameservers: 
        addresses: [192.168.1.1]
      parameters:
        stp: off
        forward-delay: 9
        hello-time: 2
        max-age: 12

Some additional netplan commands:

• "sudo netplan --debug apply" To apply any changes to the network configuration.
• "sudo netplan --debug generate" To generate backend specific configuration files.
• "sudo netplan try" To try a new neplan configuration with automatic roll back.

Full VM Network Setup 18.04

The VM netplan yaml configuration file for static LAN IP address: "/etc/netplan/network.yaml" as follows:

network:
  version: 2
  renderer: networkd
  ethernets:
    ens3:
      addresses: [192.168.1.12/24]
      gateway4: 192.168.1.1
      nameservers:
         addresses: [192.168.1.1]

I also created a bridge definition file for libvirt as recommeded by netplan.io examples:

Create a file br0.xml, "vim ~/br0.xml" and add following to it:

<network>
  <name>br0</name>
  <forward mode='bridge'/>
  <bridge name='br0'/>
</network>

Next have libvirt add the new network and autostart it:

• sudo virsh net-define ~/br0.xml
• sudo virsh net-start br0
• sudo virsh net-autostart br0

The qemu defined networks can be listed with the command: "virsh net-list --all"

You can list networks with "networkctl list"

Some helpful commands and comments:

• To see bridge status information: "brctl show"
• To see bond setup status: "cat /proc/net/bonding/bond0"
• To list network configuration: "ifconfig", "ip a", "ip route"
• Kernal IP routing table: "route"
• The NetworkManager is not required on a server, as the base ifconfig and related commands provide full functionality. NetworkManager may conflict with base configuration. Remove with "sudo apt remove NetworkManager". (To see information on system network start-up and ongoing status: "sudo systemctl status NetworkManager" or more comprehensivily "journalctl -u NetworkManager")

Setup NTP server

The NTP server setup is quite simple, I used the reference from Using chrony on Ubuntu 18.04. I replace the pool servers with my local ones, "sudo vim /etc/ntp.conf".

Some NTP tips:

• To install: "sudo apt install ntp ntpdate"
• To edit main configuration file: "sudo nano /etc/ntp.conf"
• The NTP Pool Time Servers page provides the regional NTP servers/pools
• The systemctl command (status, stop, start, restart): "systemctl status ntp.service"

Setting System Time - Time Zone

Use the "timedatectl" command to interogate and modify time and date information as required, mainly used to set local timezone and daylight savings parameters. The following commands are typical:

• "timedatectl" and "timedatectl status" to list current system time date information.
• "timedatectl list-timezones" to list available time zones in timedatectl.
• "sudo timedatectl set-timezone Australia/Perth" to change timezone to desired.

BASH Customisation

The standard BASH colour configuration uses a blue colour for listing directories (ls) which is difficult to read on a black background. While this is the "standard colour", due to the impracticality I have decided to change it.

The personal BASH user configuration file is: "~/.bashrc". Simply add the following line to this file: "LS_COLORS='di=1;32' ; export LS_COLORS" The code 1;32; is for a light green colour.

The .bashrc file also has a number of other interesting "features" and options, such as aliases and colour prompts. If you turn on the colour prompt option (force_color_prompt=yes), again the dark blue colour may be difficult to read so I change the prompt color code from 34 to 36.

To update the terminal, without logging off type: ". ~/.bashrc" or "source ~/.bashrc". The command "exec bash" will also work.

BASH History Customisation and Use

How To Use Bash History Commands and Expansions on a Linux VPS

VIM Customisation

I use the VI (or VIM) editor. It comes standard on most Linux and UNIX distributions, or can otherwise be installed. A key feature I configure is the VIM colour scheme, as the standard colour scheme does not work well with black background terminal windows I prefer to use. Simply create the file on home directory, ".vimrc" ("sudo vim .vimrc") and add the line ":colorscheme desert".

The different VIM colour scheme definition files are located at "/usr/share/vim/vim74/colors"

VIM Text Editor

A powerful text editor, standard in most Linux distributions and available in Windows. Need some time and effort to learn though, particularly if moving from graphical user environment.

Some Informative Links:

• Simple VIM Reference!!!
• Troubleshooters - VI & Vim!!!
• The VIM Wiki, contains a lot of VIM help / user information.
• The VIM Wiki -Copy, cut and paste
• The VIM Wiki -Copy, Search and replace
• VIM FAQ
• Seven habits of effective text editing

Some Quick tips:

• There are two (2) main modes: Command mode and Insertion mode. You only normally type text in Insertion mode. The Esc (escape) key enters command mode and the i or INS(insert) keys return to Insertion mode.
• If like me you use a keyboard without an insert key, eg. Microsoft Surface, you can get into insert mode directly from command mode by typing i. When you open VIM you are in command mode, so simply type i (or insert) to get into insert mode.
• To copy, cut and paste:
  • First go into command mode (ESC or CTRL-[)
  • Move using cursor keys to place to start highlight, hit v key and highlight area to be copied (or cut)
  • key y to copy, or d to cut
  • Move to place to paste, key P to paste before cursor or p to paste after

Rsync - File sycronisation, full feature file copy

There is a lot of existing information on using Rsync published

• A Practical Guide to Using rsync!
• How to backup with rsync
• Grsync: Home - A graphical front end for Rsync
• rsync(1) Rsync online manual page

Simlinks

A symlink is a soft or hard link to a directory location to another directory location or file. I am only interested in the soft link. It effectivily allows a directory tree to be made for different non-structured directory locations, even across partitions.

Simple use is: 'ln -s "path/directory or file" "path/symlink name", where option -s is to create a symlink. See ln --help or man ln for more information. Another good reference is The Geek Stuff The Ultimate Linux Soft and Hard Link Guide (10 Ln Command Examples)

To remove symlink 'rm "path/symlink name"'

To list symlink 'ls "path/symlink name"'

To list symlink directory contents 'ls "path/symlink name/"'

Symlink ownership is not particularly important as it has full permissions (777) and file access is determined by real file permissions.

KVM

Use the built-in clone facility: "sudo virt-clone --connect=qemu://example.com/system -o this-vm -n that-vm --auto-clone", Which will make a copy of this-vm, named that-vm, and takes care of duplicating storage devices.

to list all defined virtual machines "virsh list --all"

To dump a virtual machine xml definition to a file: "virsh dumpxml {vir_machine} > /dir/file.xml"

Modify the following xml tags:

• <name>VM_name</name> be careful not to use an existing VM name, running, paused or stopped.
• <uuid>869d5df0-13fa-47a0-a11e-a728ae65c86d</uuid>. Use "uuidgen" to generate a new unique uuid.
• Change as required the VM source file: <source file='/path_to/vm_image_file.img'/>
• <mac address='52:54:00:70:a9:a1'/> Cant be the same on the same local network....

To convert the xml flie back to a virtual machine difinition: "sudo virsh define /path_to/name_VM_xml_file.xml"

The VM xml file can be edited directly using the command" virsh edit VM_name"

To get virtual immage disk information "sudo qemu-img info /path_to/name_VM_file.img"

A compacted qcow2 image can be created using the following command: "sudo qemu-img convert -O qcow2 -c old.qcow2 new_compacted_version_of_old.qcow2