SHDesigns: Embedded Systems Design, Consulting and Developer Resources Page hits:

The www.shdesigns.org server

If you are curious about the hardware involved in providing these web pages, here's a description. These pages are located in two locations:
http://shdesigns.org - 1and1.com hosted pages - http://www.shdesigns.dyndns.org - Web server here in my office

This server mirrors the web site and used to be the primary server. It is cheaper to use hosting and does not tie up my DSL line.

Below are the servers for www.shdesigns.dyndns.org.


Switch is Linksys 8-port 10/100mbit. Not shown is a Xyxel 5-Port Gigabit switch.
Cabinet is a modified wardrobe. Perfect size and inexpensive (24"deep.)

UPS: Belkin 1200VA

 Linux Router:

  • CPU: Pentium III 866mHz
  • OS: Gentoo
  • 100mbit Ethernet x2
  • Memory: 128mb
  • 2 Gig IDE
  • 19" Rackmount case
  • vtund VPN server
  • PPPoE client (Roaring penguin.)
  • Dynamic DNS updates
  • MyNetwatchman client

(Has since been moved to a Soekris 4801, 266mHz, 128mB RAM and 8 gig compact Flash disk.)

Web/file Server

  • Dual PIII-1000mHz
  • Disk: dual 70 gig Ultra-320 SCSI drives in RAID 1
  • Gentoo Linux
  • 1000mbit LAN
  • 512 meg ECC RAM.
  • Applications:
    • Samba file sharing (with encrypted passwords)
    • Mgetty+Sendfax fax server (receives faxes and then e-mails them to me as an attachment.)
    • Apache Web server
    • Print server (LPD and Samba)
    • Eggdrop IRC bot.
    • Postfix email server

Email/Backup Server:

  • Gentoo
  • PopTop PPPtP server
  • PIII 650 mhz
  • 96mb RAM
  • IRC chat server

The Web server runs fast with little hardware. This server has been running Linux non-stop since 1994 with no problems. It started life on an old '386 system with 8 megs of RAM. As I upgraded development and test systems, old hardware has been used to upgrade this server. The current system runs with no swap file needed. Only 64 megs of RAM would be needed for good performance, but I had some extra. Without X-Windows, Linux will run fine on 32 megs or less.

Samba provides file and print services for my local network to the web server. This is not accessible from the internet, only on the local network. This is where I keep most of my working files so I can work at any PC on my network. The local network consists of a 5-port ZyXel Gigabit switch and a 100mbit, full-duplex switch. The Linux server with Samba serves files at over 40 mBytes/sec.

On the monitor is the ADSL modem (ZyXel). Top shelf has the network switch and Linux router/firewall. The modem provides me with an 1472kbit down and 256k up link to the internet. The Linux firewall only allows web accesses to enter my Web server, so the system is safe from most hackers. All my development machines can access the internet and can not be accessed from the internet. The firewall is set up as a "black hole" to any unwanted traffic. Unwanted requests from the internet are completely ignored rather than denied so port scanners will not even see a "denied" response.

Since October 2001, shdesigns.org has become an official domain via Dotster.com and dyndns.org. Dyndns.org allows me to have a dynamic IP address but still always have a valid DNS address. Dotster provides the domain name services that use dyndns.org for find my server. This has worked flawlessly for since mid-2000. The web server actually hosts several domains on one dynamic IP.

As a VPN and email server, another Linux box only allows a secure, encrypted connection to the local network so it is also secure. The Linux router also provides an additional VPN link to other Linux servers. If I need to access a clients network, I add a VPN server at their site. This provides me a fast, secure, private link to their site. Currently I have two links connected to the Linux router. The Email server is actually my old web server. When time permits, it will be migrated to the new box.

The Backup server has been merged into the Email server. So there are now only 3 PC's.

4 Servers to implement this web site is overkill. The router would work on an old 486. But these are old PC's built from spare parts. Having separate servers is more secure as if one is comprimized, the others are isolated. Since the Web server is also a file server, I have upgraded it with a fast disk and Gigabit. Otherwise, almost no money was spent. The router was built mainly from spare parts, but the case was expensive. A rackmount case fits nice here. The backup and emil servers were free discards from a client.

Update 12-10-2005: The are now only two PC's, the file/web server and the backup server. The router has been moved to a Soekris box. This cuts down noise and power costs. I also replaced the linksys switch with a 24-port Dell managed switch with 2 gigabit ports.

Of course, a UPS keeps everything humming along when power goes out. That happens often here so I also have a backup generator. . The cabinet has doors that are kept closed so I don't have to listen to the noise. A set of 4 internal fans keep the contents cool.

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