Bootable Live CD/DVD Development
This page is a summary of discussion from the
SVWUX mail list about how to make and what to put on bootable Live CD/DVD media that would be useful for SVWUX.
Functions and Uses of a Live CD/DVD
The purpose of this Live CD/DVD effort is to support the SVWUX Emergency Wireless Network. Any other Amateur Radio or Wi-Fi function that finds a use for it is considered a plus.
Bear in mind that one of the primary functions of the SVWUX Emergency Wireless Network is to support an Emergency Operations Center. We are developing this in conjunction with the
San Jose Radio Amateur Civil Emergency Services (SJ RACES) in the Emergency Operations Center of the City of San Jose, which is the 10th largest city in America and 3rd largest city in California (behind Los Angeles and San Diego) measured by population within an incorporated municipal boundary. We hope and expect it will be useful to a wide array of other local governments' emergency services organizations both larger and smaller.
Note that unlike a corporate IT environment, the emphasis is not around customization for an individual. Though that is allowed as a secondary function. In the EOC environment, the primary function is to customize to support various roles in the
Incident Command System. See the
FEMA ICS Resource Center for details including ICS forms and position checklists.
Ian suggested possible uses including the following:
- an SJ EOC radio room terminal
- an APRS station
- a display server connected to a video projector (i.e. presentations)
- an Asterisk-based voice terminal
- a video conference terminal
- a Wi-Fi router
- a Red Cross shelter e-mail terminal
- an EWN network administration node
- specialized apps for various Incident Command System roles
- or add other functions to the list
Keep it Simple, Stupid!
The "KISS Principle" (a.k.a. Keep it Simple, Stupid!) of engineering is highly recommended here.
While we might pack a lot of complexity underneath, it needs to present a simple interface to the user normally.
Layers of the SVWUX EWN and SJ EOC Systems
We'll need to separate the various software subsystems in order to keep things organized and control the complexity of the system. Each "layer" of the architecture depends on the layers with lower numbers. A layering model was posted on the list which was almost identical to the
OSI Reference Model. With a small modification, the OSI layer numbering is merged in here with examples from the e-mail discussion of what we'll put in each layer.
| # | Layer | Example functionality of layer |
|---|
| 0 | The Zero layer | Power, UPS's, heating/air conditioning, and physical security |
| 1 | The Physical layer | cabling, computing hardware, connectors, antennas, radio propogation |
| 1.5 | The OS layer | Linux versions, Xen, Grid, Clustering, Isconf, CD's/DVD's, Bootable USB Memory sticks |
| 2 | The Data Link layer | Ethernet, 802.11a/b/g/n Wi-Fi, WiMAX, AX.25, Ricochet, VLANS, WEP, WPA |
| 3 | The Network layer | IPv4, IPv6, IP network numerology, routing (OSPF, IS-IS, BGP), IPsec/VPN's, firewalls, traffic shaping |
| 4 | The Transport layer | TCP, UDP, IGMP |
| 5 | The Session/Services Layer | HTTP, LDAP, RADIUS, DNS, DHCP, TLS/SSL, VoIP (SIP, H.323, IAX), Instant Messaging, SMTP, NNTP |
| 6 | The Presentation layer | BBS's, blogs, web message forms, web-mail, Netnews, Asterisk, Outpost |
| 7 | The Application layer | data flow through the EOC Radio room, the EOC interface |
Base Platform
Of course, there were immediately suggestions for different Linux distributions to use for the Live CD/DVD. We're not going to argue over which one to use - this is a meritocracy system so we're going to allow them to compete to show which one is "best" for the job. Whoever builds the best bootable Live CD or DVD for this purpose will get their favorite platform into the system.
Of course, competition for the OS and packaging of the Live CD/DVD could and should still mean sharing the software and configurations for Layers 2-7 of the system architecture.
William pointed out useful documentation for any Linux distribution at
http://www.linux-live.org/
Fedora Linux
Ian Kluft suggested a
Fedora Linux based Live CD/DVD.
See the
Fedora Live CD HOWTO.
Debian/Ubuntu Linux
Rafael Skodlar suggested a
Debian or
Ubuntu Linux based Live CD/DVD.
See the
DebianLive HOWTOs or the
Ubuntu Live CD Customization.
Local Data Storage
Of course, when booting from a Live CD/DVD, there is no writable storage on the boot media. System configuration and user data are separate but related issues in this.
Configuration and Customizability
Ian suggested in the discussion that the following sources of configuration and user data could be used. A program that we will need to write would determine at boot time where available configuration data exists, and obtain it.
- files on an installed hard drive, if present
- a USB or other removable storage device
- an HTTP server (if the network comes up)
For the network option, if the network comes up, a configuration program on the Live CD/DVD could check if a host named "ewn-config" exists on the local network. If so, it can be used as a web server to obtain customized configuration data for the machine.
User Data
William suggests a method he will use to accomplish storage of user data. His Live CD will support the following modes:
1) Boot from CD. No changes saved on reboot.
2) Boot from CD, save changes on a USB device for next boot.
3) boot from CD, install on external or internal hard drive, then reboot from that drive.
4) Boot from CD, then NFS connect to server for /home and /etc. This option will (of course) require a server up and running at all times.
Suggested Functionality
Craig started a list of functionality he would like to see in the client and server environments. These could be, for example, separate CDs or all on one DVD.
Absolutely Required for a Live CD/DVD Client
- Web browser (doesn't need all the bells and whistles) such as FireFox or something simpler
- VoIP client (don't know which one yet, but SIP, H.323, and IAX if possible),
- SSH
- IPsec of some sort
- DHCP client
- basic networking stacks (IPv4/6) but includes a module for every possible networking device driver
- lots of USB driver modules so people can use their own thumb drives, etc.
Might Be Cool To Have for a Live CD/DVD Client
- IM client (as many protocols as makes sense)
- some simple word processing capability
- printing capability (to a network printer)
- a simple-to-use GUI Netnews reader
Absolutely Required for a Server
This includes all of Client stuff.
Might Be Cool To Have for a Live-CD Server
Might Be Cool To Have for an Installed Server
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